I think it's dangerous to generalise what is best for Autistic people, since we are such a diverse bunch. I've got dyscalculia (basically dyslexia but with numbers), so science, math, and engineering were out of the question for me. However, I found that studying arts (social sciences and international dev.) in university was the best thing I ever did for myself, especially in terms of finding an Autism friendly career field. If I'd never gone back to university after a lengthy hiatus in my early twenties, I'd probably still be miserably floating between ****** jobs in hospitality and the service industries. I really hated working in those fields and had a hard time keeping a job, and became very depressed. Even so, I was very against going back to university, as I firmly believed it was a waste of time and money.
Once I started studying I realised it was the happiest I've ever been. I've pursued postgraduate studies, am teaching university classes (which I find incredibly fulfilling), and I'm able to research a topic close to my heart and make a career out of my Autistic traits. I'm financially stable because the pay is great compared to service work; I am able to work in teaching roughly 6 months of the year (all throughout the academic year) and make the equivalent amount of money that I'd have if I worked ~20 hours per week in service, all year. The rest of the year I just focus on my own research and mostly work from home. This leaves me lots of time to recharge and avoid burnouts. Nobody stands over my shoulder and watches me work, as most of what I do is independent and can be done alone in my office or at home--even when I'm teaching, I'm the one in charge. Nobody monitors my bathroom breaks, and I can take coffee or lunch for as long as I want, whenever I want. It's the best job I've ever had.
I'm even contributing to Autism research, because I believe that achieving representation in this area is an incredibly important step for the Neurodiversity movement. I am accepted for who I am, and being Autistic is even seen as a strength in my line of work--I'm known as somebody who gets things done, as I have a great drive and focus, I'm creative, and I achieve a very high quality of work whether in teaching, research, or otherwise. I'm socially accepted and included amongst my peers (coffees, lunches, some great friends at work, etc.), my department is friendly and accepting, and I'm 'out' to many of my colleagues, which has been a really positive experience--I never could've come 'out' in my non-academic workplaces. University can be an excellent choice for some Autistic people! I can't stress that enough.