For myself, I tend to avoid dependencies that I didn’t write.
I use a ton of my own packages. Most of my published work is stuff that I developed for my own consumption. I publish them as standalone projects; complete with tests and documentation. Doing it this way, vastly improves the Quality of my work. It’s a pattern that I have been observing in highly competent engineers, for decades. I make these packages available for others to use, but don’t really care, whether or not they use them (which is good, because very few people use my stuff).
I think, in all my projects, I only use four external dependencies, and two of them are in an experimental project (one, being ffmpeg, and the other, a simple built-in Webserver package). A third, is a paid extension, in a “semi-experimental” project (a SOAP library in an ONVIF driver). The fourth, is a keychain wrapper that I use in a couple of projects. It is something I could write, myself, but appreciate not having to. I think I might use VLCLib somewhere, but I'm not sure if I have published it. I know that I played with it, at one time.
If I do use an external dependency, I check the code, and the author. I don’t do a full audit, but I make sure that it is well-written and maintainable, in case I need to pin/fork it. If they offer it as paid, I’ll often use that option, unless they are asking a ridiculous amount (in which case, I’ll find another option). The presence of a paid option is generally a sign that the developer is serious about supporting their library. I will check out the author. I tend to look for experience and competence, as general qualities.
If I find issues, or have requests, I’ll communicate with the author, through their preferred channel (like GitHub issues). I try to be respectful and polite.
I do use a number of StackOverflow-inspired (or other sources) snippets. When I do that, I never use the code directly, but take it apart, and put it back together, in my style. I also reference the source, in my headerdoc comments. I always make sure that I completely understand the code.
I only have one project that I authored, “go viral,” and I have turned it over, completely, to a very capable team of folks. I no longer have much to do with the project, and that’s by design. I”m very glad that it took off, as it helps a lot of folks, and I’m extremely grateful to the team that adopted it. I trust them to be good stewards.