Yeah generally, technology is currently at its peak, it’s not just Apple. Phones have been the same for a few years and more people are starting to hold onto their phones for longer years because there aren’t enough compelling reasons to upgrade anymore.
But just like cars and computers, you don’t need to change them every year, and the same thing applies on phones right now. I understand that having the latest tech is cool and all, but there will always be something new every year. So yeah, I think upgrading every 3-4 generations has just become a more reasonable choice to most people.