I've had a live FTTP service since January and just like when I went from dial-up to ADSL, I don't think I'd want to go back.
I would hope that over time, the monthly service charge will decrease to a point to that of ADSL as the customer wouldn't have a choice over how their broadband and phone service was delivered as not everyone will want to use mobile networks for everything and some just won't be able to.
Should also discourage copper cable theft which I'd imagine costs BT and it's insurers a fair bit due to copper prices which is likely to have been a factor in this decision.
It appears as though Virgin are sldo going down the full fibre route where they are extending their network under Project Lightning as opposed to using cable, probably for the same reason.
Then there's CityFibre.
I've said before I'd like to see OR separated from BT and to be owned equally by all the Communications Providers that use it's services (similar to LINX) but this is unlikely and I don't think anyone would want to take on the copper loop network.
There is indeed the issue about how long the battery back up on an ONT would support a voice service for though in the event of an extended power outage.
Virgin (ADSL) => Namesco => Newnet => O2 => Plusnet => Zen => Newnet => Zen => Freeola => Vivaciti (using O2 Wholesale DSL) => Xilo (C&W Wholesale) => Xilo (O2 Wholesale) => Xilo (TT Wholesale due to O2 Wholesale closure) => Zen LLU => Zen FTTP (39.5 Mbps down, 9.5 Mbps up)
Router: Netgear D6400
Note: I don't lay turf for anyone. astro or otherwise, all views and opinions expressed are my own based on experience.