Ah, that one, too. Sometimes even if you're:

A. A developer

B. That is familiar with the software stack used by the application

C. Has enough time and energy to investigate the root cause of the bug or a proper design for the feature

D. Has enough time and energy to design the fix/feature, implement it properly, write tests, jump through all the hoops

E. Send the pull request

... sometimes the PR still languishes for years or the nightmare scenario, is discarded during a big rewrite that doesn't actually cover this requirement...

So even the code being out there isn't a silver bullet.