Edited to clarify.
Things to consider: How much of your data would you be comfortable letting Lemmy sell vs Reddit? If Zuck treated users better, would you be more accepting of Meta monetizing your data every way possible? When it comes to using something for free (tangible or intangible) do you accept a company selling your personal information if their practices align with what you feel is fair?
I don’t really give enough of a damn to draw a line. Either a service is useful enough that I want to use it, or it isn’t. I don’t give a damn if they sell user data to cover it. Nothing is free, and I’d damn well rather pay with trivial data than my actual money