All the old people have learned the old systems (C, Perl, etc) and don't want to have to learn something new, whereas young people are happy to use something newer and better (Rust, Typescript, etc.) because they don't mind learning and don't have a ton of old knowledge to throw away.

Yes that's a big generalisation and there are plenty of exceptions, but in my experience it's broadly true.

I work on an open source project which has a C component. I offered them our closed source C++ version which is way better and fixes a load of issues... Not interested. They learnt C in the 70s and don't see why they should have to change.

Actually that project is a mix of old curmudgeons and young PhD students so there is a bit of a mismatch, but I didn't feel like fighting the naysaying so...