How much wifi and open-source do you really want?

If you are willing to go with commercial hardware + open source firmware (OpenWRT) you might want to check the table of hardware of OpenWrt at https://openwrt.org/toh/views/toh_available_16128_ax-wifi and https://openwrt.org/toh/views/toh_available_864_ac-wifi. One solid pick for the future might be the Netgear WAX2* line. One of those models is now fully supported the others are on the way. If you don’t mind having older wifi a Netgear R7800 is solid.

If you want full open-source hardware and software you need a more exotic brand like this https://www.banana-pi.org/en/bananapi-router/.

Both solutions will lead to OpenWRT when it comes to software, it is better than any commercial firmware but there’s a catch about open-source wifi. The best performing wifi chips are Broadcom and those don’t usually see open-source software support**. MediaTek is the open-source alternative and while they work fine they can’t, unfortunately, beat Broadcom. As most hardware is Broadcom they have hacks that go behind the published wifi standards and get it go a few megabytes/second faster and/or improve the range a bit.

** DD-WRT is another “open-source” firmware that has a specific agreement with Broadcom to allow them to use their proprietary drivers and distribute them as blob with their firmware. While it works don’t expect compatibility with newer hardware nor a bug free solution like OpenWRT is.