I feel like there should be a course for passing these exams run by ex-FAANG employees. Perhaps a bootcamp.
2. Some of these firms occasionally host coaching sessions for referrals. Ask your friends if one is currently running.
3. "You don't need H1Bs, just lower your hiring bar" is a criticism that is a bit less applicable to firms with a high hiring bar, than to firms with a low hiring bar. If you are, in fact, talent-limited, an H1B will actually cost you more than a local worker. (Lawyers, immigration sponsorship, uncertainty in whether the visa will actually arrive, aren't cheap - and FAANG does not have a reputation for exploiting their H1B hires.)
I'd like to practice this, any recommendations?
If you don't want to pay, just get the list of former questions from the internet. [1]
Many of those questions may no longer be asked, but if you can ace them, you should have few problems with similar questions/variants thereof.
This is not a skillset that develops from doing your day job. You have to deliberately practice to get good at this.
[1] https://www.interviewcake.com/google-interview-questions
That it also rejects some good candidates is fine, there's always more candidates for FAANG jobs. (Few competitors pay FAANG salaries.)