I had a perfectly functional Galaxy A71 this time last year, still had great battery life, etc.

I had to replace it because it only has 5 years of support. Samsung offers 7 years of support but only on their top tier phones.

Google offer 7 years, even on their A series phones so I chose a pixel 9a. It's fine, I don't love it or hate it, but it's not doing anything I care about better than my last phone.