Context matters. That's the key point here.
Plus your two examples out of a hundred or so examples doesn't make it common either (or maybe one in a half examples since apt/apt-get/apt-cache are the three Debian programs under APT umbrella).
[1] there was no way this project was going to continue despite their nonsense about "broadening the options in the community", they knew what they were doing
Many OSS projects (and pretty much all of mine) were started to scratch a particular itch, so if that itch gets scratched by another project, I'm not terribly concerned.
It's more problematic if the competition is a half assed solution that, by virtue of being backed by a larger company, still sucks the oxygen out of the space you're trying to serve.