The OpenWrt One is really not a great piece of hardware. No 6GHz, and only two Ethernet ports, one of which is only 1Gbit. The latest GL.iNet products are apparently better, but also apparently don't run stock OpenWrt, only a fork of it. In other words, there's still plenty of room in the market for good routers with open-source firmware.
Probably because the cutting edge hardware doesn't have open enough drivers.