Which is not so difficult, because that busy person is in the same organisation as you, and therefor working towards the same goal.
Fixing that bug is much more difficult if that person is in an outside organisation, serving many other customers on the same code base (with possible conflicting needs), and/or is not actually in any way accountable for it (open source).
Hopefully. But not necessarily. This argument is spinning in circles. In house projects can be abandoned just as oppen-source ones can. For me that was Powermock for example.
{evil laugh.mp3}…
Ideally yes but in reality: all teams have bottlenecks, and nearly all teams have assholes. Is fixing your problem on their OKR or whatever.
Free / open source code can be fixed by anyone: the volunteer owner (who you could even bribe to fix it), any contractor with experience, or someone in the org. This is the beauty with free software. It enables people to fix their printer drivers even if they didn’t write it originally.
To have a fix accepted on an OSS project means fixing it not just for your use case but also for every other user of the project, on every target platform, while aligning with the goals of that project. If you can get anyone to look at the PR in the first place. Assuming you've used the framework to save time, you probably don't have time to go through all that and your deadline will not wait a month or six for your code to make it into a release. Depending on your employer you may well need internal permission and legal sign-off to contribute to an OSS project in company time which is yet another hoop to jump through; though that goes for forking too.