That's because the system was sold with a lie or has otherwise been co-opted with revisions over the years.

It was supposed to be for hiring wernher von braun type world leading experts in their field.

It was never supposed to be for hiring a bunch of code plumbers, which is what 99.9% of this industry consists of.

I’ve rarely seen them used for that purpose, but of course that’s my personal observation and I have no data about it. A lot of H1B folks I worked with were solid backend/mobile devs. I enjoyed working with most of them but it’d be a stretch to say they were uniquely qualified. I do notice they feel a lot of pressure to never push back on anything due to how they set up the H1B system. Not always the case but often. I always felt that they were being exploited in that way.