I've seen that too - in the nearby town (Openreach/Virgin/CityFibre) CF still seem to do their own thing underground but happily run fibre up OR's poles in overhead areas as that is presumably a bit cheaper than digging all the way like Virgin & its predecessors did.Trooli is PIA only AFAIK. CityFibre is a strange split, sometimes they use PIA and sometimes they build it themselves.
As for my own area, maybe it is microduct then, as each prospective customer has a new duct up to the property line. My experience comes from inside the exchanges, not outside...