> ... a problem domain you don't fully understand and don't have time to understand.
One resolution is to create products that address problems. Then, you can justify time in understanding and improving, because it's amortised over many users.
Of course there's still pressures, and technology still moves, but it's not cut and paste and pray.
Or go and work in that industry. I work in finance and the office has plenty of older programmers who have been trained in the theory of what they're working on.
Being a good software engineer still puts you in a large group. Being a good software engineer with good domain specific knowledge instantly puts you in a much smaller group.
It can also be much more satisfying work. And an awful lot more secure (depending on the firm) compared to starting out on your own.
Trying to be a rockstar competing on your coding merits alone is going to be damn hard to keep going for 30+ years.
Of course there's still pressures, and technology still moves, but it's not cut and paste and pray.