US ISPs regularly get government subsidies. Hell they took 200 billion to start building fiber in 1996, then they didn't do it.
Second, to the extent that tax breaks, etc, were handed out, it wasn't combined with the kind of political will you see in European countries or Asian countries. In South Korea, wiring Seoul up with fiber is a politically tractable proposal. In the U.S., wiring New York and Chicago and LA up with fiber is a political non-starter. In the U.S., rural votes count about 2x as much as urban votes, so to the extent that broadband appears on the political radar, it's all about making sure people in rural Kentucky can get DSL, not making sure people in major cities can get fiber.