Based on a few of your comments, I’m assuming you are in high school, so please correct me if I am wrong.
First off, you do not need to pick a career at this stage in your life. There are many things you don’t even know exist. There are opportunities that will exist in five years that don’t exist today. And life transforms, and you may end up having multiple professions, not necessarily sticking with one for the rest of your life. That’s one of the reasons to make sure that you make sure you have transferable skills and a strong base of writing, synthesizing, and analyzing as those are skills that will hold you in good stead in almost any profession.
Interview people in the professions that you’re interested in. Ask if you can shadow them at work. See if there is a forum or message board for people in the profession and read what kind of comments they’re making. If possible, see if you can get an internship. Also, don’t overlook the Occupational Outlook Handbook from the government that has a lot of basic information, including things like the typical number of hours worked. If you take all of these steps, will it be foolproof? No, but you’re likely to have a much better sense of whether it’s the right fit for you.
Animation and the technology behind it is not one of my areas of expertise. But I would say research the specific departments you’re interested in. In architecture, for instance, some departments are very heavy on the design aspect of architecture while others place more emphasis on the technology and science of the materials while others might have more of a focus on the environmental impacts of architecture. These programs might all meet the accreditation requirements, but they have varying foci. I imagine the same may well be true for animation. Look at the curriculum requirements for the major and the course descriptions…are there schools that delve more into the science of the technology?
Also, reach out to some professors. Ask them these questions. See if the science behind the technology is part of the curriculum, and if not, what types of sciences/fields would best be studied to get that background? Find a college that offers majors in both animation and that other science and go along both paths until you see where your interests truly lie. You might end up double majoring, or getting a minor in one, or after just a course or two decide that you’re no longer interested in one or either of the fields.
With respect to your concern about competing with students for engineering/CS programs, don’t forget that many (if not most) universities are very accepting of students in these majors. If you’re looking at the most selective American universities then they often are not admitting by major anyway. But the highly rejective universities are challenging for anyone to get into…there are simply far more qualified applicants than there are spots. If you’re not particularly interested in engineering/CS, however, then I would not recommend studying them as if you’re not interested in a subject there’s little use in trying to use that subject for a career.