Interviewing with hedge funds has been the worst experience of my career

Over the last year, I interviewed with two well-known hedge funds and one investment firm, and the experiences were strangely similar.

The first hedge fund dragged the process out for months, hinted at an offer, never turned the verbal discussions into anything official, and then sent a generic rejection email. If I wrote out the full experience, people would probably think I made it up.

The second hedge fund had me do an LLM case study and an IQ test, then completely ghosted me.

The third company, an investment firm, put me through multiple rounds ranging from hand-solved probability questions to LLM case studies. I do not mind a tough onsite process, but what bothered me was the sheer breadth of the interviews and the fact that they eventually stopped responding to my follow-ups altogether.

It feels weird that I have had such similar experiences across companies in the same space. Does this say something about the industry, or am I doing something wrong?

Edit: Best part is 2 out of these 3, I never even applied. They reached out on LinkedIn.