Hyperoptic are a lot of Hype and not much Optic.
For a start, as others have pointed out, its not their network (although their sales reps like to talk like it is).
Then there's the fact that they're only interested in "low-hanging fruit", multi-tenant dwellings (a.k.a. blocks of flats). And even then, they are only FTTB (fibre to the basement). They use CAT5/CAT6 to the door.
All sorts of other things too. But I shall not be going in to those in a public place.