There's an old quote that I've seen attributed to lots of different people that for this situation can be paraphrased:
"Some people have 25 years of experience in a field while others have one year of experience repeated 25 times"
So yeah, anyone who is developing software and keeps learning new things and pushing their boundaries is going to improve quite a bit over those years, but someone who just sticks with the same language/framework and basically reimplements the same CRUD app over and over is probably not going to knock your socks off no matter how long they've been at it.
Source: I'm a 39 year old developer and have worked with fantastic older developers and terrible older developers.
"Some people have 25 years of experience in a field while others have one year of experience repeated 25 times"
So yeah, anyone who is developing software and keeps learning new things and pushing their boundaries is going to improve quite a bit over those years, but someone who just sticks with the same language/framework and basically reimplements the same CRUD app over and over is probably not going to knock your socks off no matter how long they've been at it.
Source: I'm a 39 year old developer and have worked with fantastic older developers and terrible older developers.