That's a good solution for geeks, not so much for everyone else. Regular people don't even update their routers, much less flash 3rd party software on them. I don't think most people even know updating your router is even a possibility.
I use Google Wifi and it updates itself. In the future I might put in a PFSense, but wifi solutions like Google Wifi/Eero/etc are the way to go if you're not a computer person.