This has a negative effect on humans doing their work with or without LLMs: curl shut down their bounty program, and GitHub just announced they're "restructuring" theirs. The author of this post also makes a case that HackerOne hasn't been honest about LLM training and use, either to hackers or to their own staff.
I'd say instead that the problem is that a lot of people don't care anymore about the quality of the work being done, and LLMs are accelerating it. Bounty programs have shifted from ways for people to report security bugs to ways for people to try to make money.