I have both. I have had more issues with the PS5 (a few crashes) and the PS5 is ugly. Plus the Xbox controller is still the better controller, and it's hard to go passed Xbox game pass.
But if you're looking at upgrading in the next 6 months then I'd recommend the PS5 over the XSX. With the Playstation Plus Subscription (which is currently on special at JB Hifi online and Amazon for $60 for 12 Months) you get some of the greatest games ever made in the PS4 collection, plus the new PS5 controller is a decent step up from the old PS4 controller, and the PS5 already has new games while everything on the XSX can be run on the Xbox One X at a lower frame rate.
Honestly, if you want to upgrade then get a PS5. If you don't want a PS5 then wait until the XSX comes down in price as there's not much on the XSX that's worth upgrading for.