Boas!
Tirando o aspecto diferente, esta parece ser a maior diferença:
https://blog.mozilla.org/security/2021/06/01/total-cookie-protection-in-private-browsing/
Tirando o aspecto diferente, esta parece ser a maior diferença:
Firefox 89 blocks cross-site cookie tracking by default in private browsing
https://blog.mozilla.org/security/2021/06/01/total-cookie-protection-in-private-browsing/https://blog.mozilla.org/security/2021/06/01/total-cookie-protection-in-private-browsing/