You have a really good phone. If it's still doing everything you want it to and still getting updates, you might consider holding off another year. Some really wicked tech is going to be coming out in the next couple of years and I think those will be the way to go
Definitely upgrade. I have the S21 Ultra 5G and it's the best phone I've ever had. Hands down. That camera upgrade, the SPEEDS and the refresh rate + display are to DIE for.