People are holding on to their devices longer and having longer term support helps those who buy in the used market.
Personally know people who hold on to devices well over the 3 year mark. Hell, I keep old phones as spares. Having them at least have security updates makes them hit the landfill slower.
If one takes care of their devices, they can last. You don't have to replace them every 2 or 3 years. Hell, currently still rocking the Pixel 6 & unless something drastically happens, I'll probably wait for the Pixel 10 or the Galaxy S25 before upgrading as my device is perfectly fine.