4:48 PM, Sunday February 16th 2020
Like 80% or 90% of art is doing practice, studies, experimenting. That is stuff you can do on your own (assuming you have the tools: a PC and software if working digital, and various art supplies if traditional).
The remaining 10% or 20% is the theory. There's really no deep secrets in art. Everything is available online and for free in some form or another. Commercial resources like Schoolism, while very good, won't make you a great artist on their own.
IMO, the benefit of art schools is that it will force you to do a lot of practice in a lot of different ways. It's for the people that need a course structure in order to actually do the work they need to do.. The exact same (and maybe even better) could be achieved self-taught. And there's even free resources with a course-like structure (DrawABox being one of them).
Another thing art schools give you is the reputation from coming from a certain art school. Certain companies seem to only hire people that come from certain schools (but you plan to be a hobbyist so this doen't apply).
Also art schools give you the opportunity to make contacts in the industry. So you have more leverage when trying to get a job (which again doesn't apply because you are hobby artist).
In summary: Just practice, practice A LOT. Then check a tiny bit of theory. Then do 10x more practice. Go up to absurd levels of study and practice. Always check back to the theory/books, read and re-read them. Specially the most basic stuff. Don't only aim for knowing about the theory, aim for mastery of it. If you do all that, there's no reason you can't achieve whatever artistic goal you propose yourself.