No, it's not. Using Matomo on my own servers has nothing to do with the way GA etc. operates - it's an equivalent of going through my own Nginx logs and parsing them to generate diagrams and so on. Of course if I share personally identifiable data with a third party, it's a completely different thing - in this case it does not matter if it comes from Matomo or web server logs.

But I agree with your conclusion: what matters is how it's being used. In this case - whether you share/sell it to others or not.*

[*] But not only: it also matters if you take adequate care in protecting personally identifiable information or not.