Thanks for raising these questions. I am confident you are not alone in your concerns.
I assume that your noting that your grandkids have more choices means they have opportunities that are at least as good as what you got, so they could start the exploration with them.
I agree that one might be skeptical of the popular ratings, even if they were written by ChEs.
It is unfair to denigrate degrees that do not lead to a job. Higher education is to fulfill the whole person and also recognize that high-schoolers might need to know themselves better before making a life-long commitment to a certain discipline. During my 47 years of teaching, I had many students who discovered that what they would find most satisfying was not chemical engineering after all – though there were more that got even more turned on.
I would hope that when one is dealing with the life of a loved one, cost, per se, is not the important factor. Rather, it should be value. In the case of education, this is a highly personal thing. Thus, I suggest that your grandkids should get the broadest range of information they can. This includes their school counselors, you and your colleagues, online exploration, university fairs and visits, etc. That way they can develop a measure of what value means to them in the run-up to deciding where to go.
I cannot recommend an on-line BSChE. The personal interactions with other students, teachers, university staff, industrial recruiters, etc., are too essential for maximum growth and development. On-line does not have these.
The interpretation of Best for career preparation partly depends on the career aspiration. Briefly: If industry bound, then I'd suggest that conventional state schools are the best for a practice-oriented undergraduate development. If academe or federal laboratory leadership is desired, then the imprimatur of a top research institution will be an advantage.
However, I think there are two alternate considerations: First, the student makes the difference. All programs use the same textbook choices, necessarily rely on teaching assistants for grading and coaching contact with students, and are accredited by the same organization (ABET). The not-chemical engineering instructors (mathematics, statistics, chemistry, physics, English, etc.) define the content of most of the classes. What the student invests in their personal development is what determines their level of preparation; that is what makes the difference. By analogy, it is not a fancy gym with modern equipment that makes the athlete skillful; it is the work that the individual does in the gym. I think student's dedication to growth is of much greater importance than the school. Partly, this means that the compatibility of the student to the school environment is important to engendering that allegiance to the purpose and dedication to the work. But also, it is the influence of family, faculty, and peers at the school that will shape the student's perspective. So, a Best school is one that invigorates and enthuses the student.
Second, education is about whole person development, the individual's preparation for career and life. It is not just about the intellectual aspect of the math and science fundamentals of chemical engineering. Preparation includes developing a perspective on life (maturing), balance, interpersonal effectiveness skills, flexibility, initiative, health and wellness, and all of those things industry seeks in hires, which are also what we seek for our children and grandchildren. You want a school that understands, and is effective in, whole person development.
Don't be misled by ranking. Schools are ranked on their graduate productivity (number of PhDs graduated, number of archival papers published, and amount of income for research). And, usually the faculty attributes that achieve top research ranking, means they have little time to invest in the undergraduates. In my opinion, the top ranked schools are not the best in preparing graduates for engineering practice careers (although top ranked schools will offer many facts to contradict that). I suggest readers investigate relevant ranking attributes for themselves. See what programs win and place in the AIChE Plant Design and Safety contests, win and place in the AIChE ChemE-Car competition, and receive Outstanding recognition for the AIChE Student Chapters. (Excellence in education is not about research awards or ACT scores.)
I was a chemical engineering professor in two US universities for the past 31 years, serving as program Head for 13 years. Prior, I rose to engineering supervision in industry for a 13 year period. Throughout, I saw the performance of a lot of students and engineers representing many colleges. In the graduate program we receive students from around the world from a large ranking diversity of colleges, and I find, the student's success seems uncorrelated to the student's origin or preparation. Similarly, in industry, we hired folks from many universities, and their success seemed uncorrelated to the stature of the program that granted their degrees. So, again, it will be the student that makes the outcome of education great, or not.
Tell the student to invest in the courses, but as well, be active in diverse extra-curricular activities related to all aspects of professional and personal wellness development. Industry seeks technically competent students as new hires. But, there are many to choose from in each graduating class, and from each university. What makes technically qualified students attractive to industry is a record of leadership effectiveness in human organizations, energetic nature, flexibility, health, creativity, diligence, cooperation, etc. Choose a program that encourages activities that permit the student to develop those essential soft skills. They are complementary to, and often more important to career and life than, the technical skills of the major.
Where ever, it will be a nominal 4-year program. The student will live in that place for 4 years, or a bit more. Consider climate and culture of the locale. Also, the student will wear the school colors for life. Like a tattoo, we all wear the brand, and express the legacy and style of our undergraduate school and locale. To have the energy to invest in the curriculum and extra-curricular activities, the student will need to want to be there. So, choose a compatible place.
There are differences in programs. Although all engineering programs seek to balance theory and application, some have faculty that lean more on the practical side and others more on the theoretical side. Look on the web sites of programs. You should be able to sense the theory and practice balance that the program has by the articles posted there. Publicity articles reveal the kind of successes that give the program administrators pride. A telling attribute of the program focus is the number of articles that relate to undergraduate successes and honors. If the program is invested in the undergraduates, then the student energy will be high; and as a result, they will graduate with strong ability and career preparation. Seek schools that are invested in whole person development.