If they had wage parity there is zero disadvantage to a US citizen. The problem is not H1B's as a concept, it's making foreign workers indentured servants paid a fraction of the wage, thus incentivizing their hiring over US citizens.
If the pool of potential workers is bigger, the wages should go down. That's still wage parity... but it's lower for everyone than it might otherwise be.
I don't follow? Why would a US citizen want to compete against 8B people for jobs instead of just 300M? Seems like the lower number is better for the citizens of the US.
Why not just decide that only white people or only men or only people born on Tuesdays can apply for the job you want?
The job should go to the most qualified person. That's how america works. If that most qualified person is actually a guy who was born in india, great. I have no problem with that. You don't get to bogart opportunity based one what zip code you were born in.
The point of the United States of America is to take care of its citizens. A "better qualified brown person" has their own country where they can apply for jobs without any restrictions. Them coming to US is a privilege, not a right. And I say it as H-1B visa holder from Europe.