And it could even get easier. I could do 20 hours a week of consulting work and still get by. I don't think I'd want to do that, but I could.
I don't know where you live or what area you work in, but I think the thing you want actually is achievable, maybe with a pay cut, or maybe not even. The fact that you're having to learn to use Rust because it's all the sudden getting used on projects says to me that you're working at some place where people put way too much of themselves into work.