Why? You don't want competition in the space?
>Or just undercutting Wi-Fi vendors like Ubiquiti who base their work on OpenWRT anyway
Huh? The older edgerouters were based on vyatta. The newer ones on a custom linux distro, neither of which are OpenWRT. They hired the original author of pfsense to build them a firewall based on Debian from scratch when they realized vyatta wasn't going to meet their needs. The UDM kernel is very much not OpenWRT
https://github.com/fabianishere/udm-kernel
Being excited about OpenWRT is great but spreading bad information and for reasons I can't fathom hoping for the downfall of other players in the market, not so much.