I switched from a Asus RT-AC68U to a mesh Netgear Orbi RBK50 2 weeks back.
I really liked the Asus one with Merlin firmware. Worked like a champ with my PiHole as well without any client side configuration.
The 3 things I hate about the Orbi are the router doing a DNS relay instead of showing my custom Pihole IP as the DNS server, no USB port to power my PiHole and the inability to create 2.4 and 5 GHz networks with different names.
My laptops connect to the 5 GHz band but reduce the speed from 866 Mbps which is the maximum a dual antenna Wifi 5 GHz card supports.
This is in spite of sitting beside the router .
But the range coverage is awesome.
The fiber optic is connected to a ONT device in my case provided by the ISP(Siti Cable) which then connects to the router WAN port using a standard ethernet cable.
Wifi 6 is not much of a concern at this point if you are not copying 10 GB files from a NAS over wifi. 4k streaming works like a champ over 5 GHz only.
Do not pay extra for the gaming features on routers (cough...cough Asus looking at you) as they provide negligible benefits unless you are a pro gramer competing in tournaments with real money.