No really. Samsung offers 4 years of os updates and 5 years of security updates. Samsung releases os updates really fast, so 5 years basically means 5 os versions.

Fairhone declares 5 os versions and 8 years of software support. Fairphone users here mentioned that fairphone is very slow with updates, so it could happen that 5 os versions really will take 8 years. If Fairphone will keep same cadence as Samsung, its 5 os versions can be coverted into 5 years.

But we have a bit of apples vs oranges here.

I personally find samsung’s policy good enough for majority of users. I expect that I will upgrade my phone every 3 - 5 years for different unpredictable today reasons anyway.