There's some good info out there from the good people that know how things should work that created the reuse tool - https://reuse.software/ - and basically the conclusion is that nobody should be updating the years on the copyright line just because it's a new year. The only useful info and what should be done is put the year when the file is created and that's it.

Edit: took me a while to find the proper thing I wanted to link - https://matija.suklje.name/how-and-why-to-properly-write-copyright-statements-in-your-code

Had to go first to the recent curl blog where the author wants to go the weird way of not having useful info at all on the files.