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?
Man, I don’t know. I try to use the products from Google, Microsoft and co as little as possible, but it’s hard to completely cut them out of my digital life. I don’t think it’s really about drawing a line - because it’s terribly difficult to gauge how much data they actually have and how valuable a service is to you - but rather about trying to avoid those services as much as reasonably possible.