it's really hard to see from the perspective of a company with a massive code base how you could possibly contribute to the ten gajillion dependencies you use, even if you wanted to

counterpoint: you don't need to actively contribute to all upstream projects, but you do need to be prepared to maintain, fix, or replace any dependency you have. if you can't do that, you should pay someone to do it. if you can't do that either then you should not be using the dependency in the first place.

yes, it can happen that you underestimate the resources needed for that, or that a project you use looked very stable and supported, but suddenly you can't find anyone who has the knowledge to fix the issue you have, but then that's simply bad luck. it can happen with company backed projects too. you need to deal with that. have no sympathy if you can't.