There's not as much money in piano as in programming.
Now that I think of it, the right answer would have been several 10k hour professions. I can't say that the products I designed in 2020 were more complex or amazing than those in 1980. It would have been a chance to achieve high levels of proficiency in multiple fields.
I think the programming field is large enough to learn and improve your whole life. You probably have to change domains, programming languages, frameworks, architectures, companies, and switch from web to mobile, from frontend to backend, from serverless to embedded -- but there are always new ways of experiencing the beginner's mind.