If you don't do the Unifi route, the Amplifi route is good too. Buy a single Amplifi HD router and see if it's enough. If no, add one more and you're likely done. It depends what you want.
I have had both and amplifi was fantastic. The only reason why I'm using a Unifi setup was pandemic boredom. Same company but Amplifi the non tech savvy version and Unifi the nerd version.
https://ca.store.ui.com/ca/en/pro/pr...h-wi-fi-system
This one you can set up within 10-20 minutes in the easiest UI I've ever seen and it's basically good to go for a long. Unifi you may have to tweak more, but not too hard to follow guides.
My parents use a single Amplifi HD router in a 2000 Sq ft house and coverage and speeds are superior to a deco p3 mesh system. One router and at least one more node should be plenty for 2800 Sq ft. Amplifi was plenty fast but not max my internet plan. My Unifi setup is like 1.5-2.5x more expensive than the amplifi HD setup, still noticeably faster and closer to max, but way more tweaking.