The UK was a bit slow to get going but is going in the right direction at a reasonable pace now. Openreach has been doing a rollout covering most people and the DCMS voucher scheme is funding independents to fill in the gaps.

I believe there will still be a rural segment relying on cellular for a while yet, but it's a shrinking minority.

Most of the altnets are not government funded - there was a ridiculous amount of money put in them from the low interest rate period, many many billions. I very much doubt they will get a good return given the crazy level of overbuild going on. I have now 4 separate infrastructure-wise FTTH networks available to me in my London apartment.

I believe (without supporting data) that most altnets that are expanding coverage to people with poor broadband are government funded. The economics in London are quite different than that of a rural village.

The vast majority aren't govt funded, the £5bn gigabit scheme is just getting going. Some may be in the future.

Economics aren't actually that different for villages (very rural single dwellings are though of course). Most villages of say 1k ppl already have fibre going to them (for VDSL cabinets), so they can buy the backhaul from Openreach.

Then it's a case of adding the actual fibre which they can use existing telegraph poles for.

There isn't really a huge difference in economics between urban suburbs and villages.

London is actually not as cheap as you'd think, because a lot of properties are apartments and that requires expensive wayleave agreements to be negotiated with the freeholder. This has significantly increased the cost, as many freeholders don't care and don't respond or want a lot of money for the permission, meaning you have to dig up the street regardless and miss a lot of properties and hope they can be added later.

Plus the cost and complexity of closing roads/streets is much higher in London than other areas.

The UK took a different approach to most other countries; and IMO was the correct one. Something like 98% of properties could get at least 30meg (via VDSL2, actually more likely to be closer to 80mbit) down, and this has been the case for nearly a decade. 50% of homes have always been able to get much faster speeds via DOCSIS cable from VM (though I will caveat with that that until VM enabled DOCSIS3.1 across their network recently it could be very hit and miss congestion wise).

In the past few years though there has been an explosion in FTTH build. 75% properties can get gigabit service now which is increasing by around about 1% every month.

The priority a decade ago really was on getting the entire country up to 'usable' internet speeds, rather than having a lot of FTTH in some areas and then very slow DSL in many other areas. Only 0.35% of UK properties are below 2mbit/sec down now (unusable), which doesn't include 4G/5G coverage, so in reality it's likely only 1 in 1000 households have utterly terrible connectivity.

So while the UK doesn't rank top of the list of median download speeds it is far less likely you are going to have bad connectivity, which IMO is a greater priority than raw download speeds.

Very few people actually need more than say 100mbit/sec day to day. It's actually hard to get gigabit around the house; most powerline adaptors and wifi solutions top out around 300mbit/sec in my experience, so unless you have ethernet in your house (very rare), the limiting factor is now on in home connectivity, not the external ISP.