What is your budget?
In general try to go for Asus, they can mesh and are usually reliable.
If you want something more advanced, look into Ubiquiti, though they will be more expensive, also read the reviews for the different components, some POE switches can get quite hot, so if you don't need it try and avoid it.
I am on Asus, and have had very little issues related to my router the last few years, but have been eyeing Ubiquiti lately...
I can second the reliability of Asus. Mine is five years old now, and still going strong.
I also second this. I have an Asus router setup with mesh nodes, and it has been running smoothly, especially since I'm hosting a plex server and occasionally multiplayer servers.
Before buying, look for secondhand ones, many people move to a different house where their previous system becomes obsolete, or they upgraded to a different beast.
One you can put openwrt on and that is fast enough for the highest 802.11 protocol your devices support
How hard is it to put openwrt on any old commodity router if it's on the compatible devices list? Is it basically just using the old router's firmware update page and loading the openwrt firmware image?
Thinking about gifting a new wifi access point for one of my friends with a crap router that doesn't even support 5ghz channels
There is usually a per-router guide on installation. Sometimes you can just use the built-in firmware flashing interface, sometimes you have to do funny things like do that twice in a row, sometimes you need to access a special interface.
I have a gl.inet router and it’s great. Super easy to setup and supports wireguard out of the box. It has some cool travel features as well.
I had a heckuva time making the signal reach the living room. Went through WPS and range extenders. The only thing that has worked was a set of four mesh routers.
No problems since.