I don’t think getting freebies from them counts as supporting them

I do. Some examples off the top of my head:

• giving them access to your stored data, by letting their code execute on your computer
• giving them access to your behavioral data (a form of biometrics), through the same
• giving them access to your system fingerprints, through both code execution and account creation
• giving them legal influence over you, by agreeing to their terms
• giving some of their legal arguments greater weight, by increasing their market share
• giving them greater sway with publishers, such as when seeking exclusivity deals, by bolstering their user count

There are probably other ways in which it supports them. Those are just the first ones to come to mind.