One big problem
Internet doesn't work for long if mains power goes out. POTS is powered by batteries at the central office. Designed that way so that the parts likely to fail are all in one place, and easy to fix.
I understand the economics and the reasons for this, but I have a soft spot for the old copper system, which, if it were allowed to, would outlive me, because it's so damn well designed and built. I have much respect for The Telephone Company, their engineers and craftspeople, may they all rest in peace.
In My World, you'd have a single fiber connection for fun, and a POTS connection for when you really need it, like when you need an ambulance and the power's out (and the little dinky made-in-China backup battery in your fiber interface has long since departed)
// don't forget who Tommy Flowers worked for...