What Does a Year Matter in Terms of Value?

[pmm21]

As I look to buy watches from time to time, I see these premium prices being demanded for slightly more current models, but I can't see why they would actually be any more valuable

i.e. If I want a 116610LN, in new condition, I can expect to pay X for a 2015 model, whereas if it were a 2018 or 2019 in the same condition, it commands a noticeably higher price.
-Or- why is a late model G serial less valuable than a scrambled serial with a card dated in the same year?

It is essentially the exact same watch, is it not?

So, aside from the obvious "one is newer" comments, which I'm sure some will feel the need to say in order to pad their post counts, can someone enlighten me?