Good question thanks. We should precise though that as @anon80779245 said that there are nuances in the effectiveness of censorship circumvention providers depending on the network.
I would phrase it like this : what are the most reliable providers in the worst cases (Iran, Turkmenistan, China, Myanmar, Russia, Cuba etc) ?
Or “if my country becomes a full digital authoritarian hell, which are the providers the most likely to save me? “
Plus Windscribe, Psiphon…?
Reading the messages above, it seems that IVPN and Proton are less reliable than Mullvad in China.
To answer my question, from what I have read, I have the impression that Mullvad, TOR and maybe Windscribe and Amnezia are the most reliable in heavy restricted countries.
Who they? Mullvad?