Yep, all H1B workers combined are less than 500K people. A tiny, tiny portion of the job market, which is like 175 million jobs

65% of H1B jobs are in one industry, “computer-related” jobs as of 2023. There are over 700,000 H1Bs in the USA, so almost half a million tech industry specific H1B jobs. Considering there are roughly 6-10 million tech jobs in total in the USA, that's 5-9% of tech jobs.