There may be many Indians, but when I was on h1b me and my colleagues were from Germany, Lithuania, Russia, Ukraine, Brazil, India. All of those moved on to other companies, even multiple times and/or went through the green card process.
The salary I got was ok for bay area standards, certainly not rockstar level but would make jaws drop in Germany. For me it was an amazing opportunity and I would recommend it to anyone to do for a while.
I’m just an outside observer but I would say it’s probably not all a scam. Most of it absolutely is though.
Generally I just see a lot of unfocused writing in this thread. Even the reply to your post is an attempt to muddy the waters with some ambiguous statement. I guess this is a community of developers and we tend to have difficulty with politics and the real world :-)