I highly doubt that consumer internet in Japan is terminating fiber directly into peoples' computers.

You run fiber to the home and gigabit ethernet or whatever internally in the premises. All your other complaints re: cost and etc aren't really an issue for last mile consumer grade fiber.

I have seen installers run a fiber drop cable across from a power pole, bring it down an outside wall , then staple it to joists under a house, cleave off the end and stick a mechanical splice on it, bang it in the power meter, all good, plug it in the fiber modem, good to go in less than 20 minutes. All this stuff uses standard components and technology that's been available for 10+ years now.

Also no one uses cat3 for data and it can't be run for 'hundreds of feet'. And LC fiber IS used in the US - that's a kind of connector not the kind of fiber

It's probably the standard "last mile" half assed solution where they decide to use existing phone lines and VDSL from a box down the street instead of biting the bullet and running fiber.