There is no requirement to demonstrate that you cannot find an American to do the job to get an H1b visa approved. If that person applies for a PERM position (needed to convert to a green card) there is. Hence the H1b is easy to game by employers to get cheap indentured servants.
With PERM (converting to a green card) they try to hide the job postings so that people will not apply so that they can get the green card approved. Some of the tricks include putting ads in the newspaper, using esoteric websites and other media such as radio instead of job boards where tech people actually look for jobs. Some Americans who have trouble finding jobs in the current market took on a side project of scraping newspaper ads and these job boards and created https://www.jobs.now/ which lists these jobs. If enough Americans that meet the minimum qualifications apply for a listed job it stops the green card process for that position, usually for 6 months before the sponsor may try again.
Also, there are a lot of stories about people getting O-1 visas via fake credential mills and research papers. Both can and are being gamed to get O-1's.
With PERM (converting to a green card) they try to hide the job postings so that people will not apply so that they can get the green card approved. Some of the tricks include putting ads in the newspaper, using esoteric websites and other media such as radio instead of job boards where tech people actually look for jobs. Some Americans who have trouble finding jobs in the current market took on a side project of scraping newspaper ads and these job boards and created https://www.jobs.now/ which lists these jobs. If enough Americans that meet the minimum qualifications apply for a listed job it stops the green card process for that position, usually for 6 months before the sponsor may try again.
Also, there are a lot of stories about people getting O-1 visas via fake credential mills and research papers. Both can and are being gamed to get O-1's.