What are you referring to exactly? If Mozilla told you "sure, we'll take your money and give you a more privacy-preserving browser", what would you want to be different about it?
Mozilla need to remove Javascript finger printing identity from the browser<p>Try it from a VPN
<a href="https://amiunique.org/" rel="nofollow">https://amiunique.org/</a>
What do you mean specifically by paid privacy tier? Mozilla offers some privacy oriented paid services... one comment here mentions VPN, then there is Monitor Plus for online data scrubbing, Firefox Relay for message masking, just from the top of my head
If you care about privacy, use the internet less. There is no world in which free things like the internet will also be privacy-respecting once it starts to generate economic output.
Something you can do for free is block all outbound traffic and configure Firefox to use an outbound HTTPS proxy where you can dynamically enforce a blocklist or default deny and an allowlist.<p>Isolate Firefox traffic and observe it some time.