I saw both. One of the top firms wanted that, another I worked at we did report (of course with a scratched minimal reproducible example)

The thing is, it's quite unlikely that your competitor hits the exact same bug. The cost of us having to keep upstream patched, tested isn't justified.

Also in HFT world there are some very similar patterns across competing companies, yet, we just saw TernFS coming out from XTX, with not much fear of competitors benefiting from it more than they do.