Even if the money had been available. you can't just spawn millions of teachers out of nothing. there aren't that many people who can and want to do the job.

Show me the lobbyist who will push for giving 700 billion a year to teachers.

That 100 billion goes to a bunch of extremely well-connected businesses who fund lobbyists to make sure the USA continues expending munitions in a series of utterly pointless, futile, wars.