99.99% of people don't even buy routers, they just use the free one that comes with the connection.
For people who do buy them, there's a number of good products out there already. Why would I trust a new product from a single person, which might drop out of support after 6 months?
Probably more like 80%. I know even some normies who go far out of their way to refuse Comcast's hardware.
My fiber ISP has full instructions for using your own router. They mention that they won't be able to offer remote support and that if you want to use your own router, you're probably okay with that.