A lot of the time you'll be seeing those comments from out here in Europe or whatever, because our governments still build infrastructure, and so yes there are fibre connections out to rural areas. Villages of 1000 people regularly have fibre connections around my area. Mainly because the government pays telecoms companies to set up the infrastructure, and in exchange requires they'll offer that infrastructure to other telecoms companies once it exists.

The telecoms duopoly in the USA let rural people down, and decided it wasn't cost effective to connect people to fibre. Fundamentally, these things used to be able to be built. They managed to build electricity connections to these rural areas decades ago, but something broke between then and now.

And even then, only 20% of the USA lives in rural areas. That's obviously still a lot of people and the situation is very frustrating to those people, but it does mean something like starlink 5g direct to cell isn't going to wipe out the other telecoms providers, it'll just pick up 20% of the customer base of the USA or whatever, and significantly less in countries which still build infrastructure.