Wifi 6 routers are better in that the underlying technology of it is better.
In the same way that that current wifi 5 routers are better for clients of all specs that connect to them, such as wireless G and wireless N, not just wifi 5 devices.
To really utilise the router you need wifi 6 devices though.
That have very easy solution 🙂
Separated AP serving "slower devices" with 20 MHz on 2.4 GHz and 40/80 MHz on 5 Ghz (Band II)
and separately 160 MHz on 5 Ghz (Band III - DFS - channel 128 / preventing older devices to try to connect there)...
Like that, maximum for everyone by their liking :))