1/ Yes, there are companies like Tata and Wipro who game the system to hire software developers at below market rate. This is absolutely a problem that should be addressed. Outright banning H-1B does solve the problem, but it is nowhere near optimal. For many skilled talents, H-1B is the only path to work in the U.S. Banning H-1B is throwing the baby out with the bathwater.

2/ No, there is no systemic difference in compensation for non-U.S. citizens at FAANG and equivalent. Compensation packages are formulaic. No one gets +/- X% just because they are a citizen or immigrant. If Google one day decides to pay H-1B 20% lower, they would lose out on a ton of qualified candidates to, say, Facebook. It'd require the entire conglomerate of FAANG, and whom they consider "peer" companies, to agree to suppress compensation for this to work [1]. It would also require everyone involved in the hiring process, many of whom were immigrants, to be onboard. I simple don't believe companies who compete for top talents would find this tradeoff worth it. I might just be living in a bubble, and am willing to be proven wrong. Just show me the data.

3/ Many successful companies are founded or led by immigrants who now happily call the U.S. their home. These are success stories that the country should celebrate, not chastise. You might think that Larry Page could've founded Google without Sergey Brin. You might be right, or wrong. The fact is we only have reality to observe. We don't have counterfactuals to compare against.

[1] I know about the Steve Jobs no-poach email. That was also 13 years ago.