True, but long term users often do not understand that if a project that is expected to make money doesn't try to acquire new userbase, it stops being relevant fast.
The big-picture view of what you're saying is "anything that does not expand dies", and I think that is a fundamental problem with the way our society works. It should be possible to succeed by just remaining stable.
It's not always about expansion but sometimes can be just about rotation.
People lose interest, people change, people die. Software is a reflection of user problems, and users are alive, therefore software must adapt. Software from 1960s can't solve problems of people from 2020s, even if the concept is the same, the binary format is different - OSes are different today. The same solutions had to be adapted to new environment just because the environment has changed.
If we'll stop trying to find new users and we'll only try to retain old ones, we automatically have a declining userbase. This is not healthy for any software project, any country, any group.