We upgraded from a basic TP Link 1200AC router to an Asus WiFi6 AX1800 “ZenMini” mesh.
Our space is just over 1100sqft, and 3 mesh points works well (we got 4 as there was a deal on two packs, but one is essentiallyredundant in our setup). Even just the main router and no mesh was already much more powerful and faster. The extra points help get to two rooms at the far end of the flat where signal was spotty before. One of our walls is over 30cm thick and the signal less than 2 metres from the router was challenging before we adjusted for better line of sight from one of the mesh points to the door.
Wifi 6 feels mostly marketing hype but the protocol does seem to be better at optimising for channel switching and handoffs between nodes (vs a friend's older setup).