You assume that people want you to use their project. For MinIO, the AGPL seems to be a way to get people into their ecosystem so they can sell exceptions. Others might want you to contribute code back.
I have no problem with contributing back: we do that all the time on MIT / BSD projects even if we don't have to. AGPL just restricts the use-cases and (apparently) there is limited legal precedence in my region to see if we don't have to give away everything that's not even related but uses it, so the lawyers (I am not a lawyer, so I cannot provide more details) say to avoid it completely. Just to be safe. And I am sure it hurts a lot of projects... There are many modern projects that are the same thing, but they don't share code because the code is agpl.