Your users can just host their own version instead of paying you.
It seems like many OSS companies mitigate this by leaving out features from the OSS version or making the deployment more difficult than it should be. I’m not complaining, I think it’s fair, but this is the reality.
It’s funny how they don’t address this one, but instead they list “oh no my code isn’t pretty” as a valid complaint against going OSS. Who cares.