Probably 90% of my coworkers in a US tech company are on a work visa. Now that there is pressure on the H1B program, my company is investing in a permanent engineering team in India. Whether this will pay off for them in the long term is a matter of debate, but it seems like the near-term future of the US engineering team is in serious doubt.

You can't just "dismantle H1B" and expect it not to backfire.