It's quite an old power supply, not many manufacturers offered much better than a 3 year warranty back then. Seasonic had a some PSU's with a 5 year warranty. Then EVGA started giving out 7 year warrentys which seemed to start a warranty war with a lot of PSU manufacturers and vendors.
It has far more than enough power for a 2080 ti and is decent quality for the time. I would have no problem using it for a while longer.