Many of those don't need anywhere close to "never need to work again" money, only "2-3 years savings, or a willingness to half-ass your job". You just need the courage to make it a priority.

It's entirely possible to do most of those as a hobby. If you do need to go full-time on it, you can usually accomplish a lot in 2-3 years, and then jump back into the workforce when you get bored with your hobbies.