I don't know what VPN protocols are used by Proton, but have found in the past that Proton can suddenly disconnect. Having a Kill Switch is not much comfort, so stopped using it. Is the latest version of Proton VPN any better?

Don't forget about protocols like:

ShadowSocks

TROJAN
VMess
VLESS

AmneziaWG
https://github.com/amnezia-vpn/amneziawg-go
https://docs.amnezia.org/documentation/amnezia-wg/

OpenConnect
https://gitlab.com/openconnect/ocserv
https://ocserv.openconnect-vpn.net/
https://habr.com/ru/articles/776256/

Many of them work great in Iran, Russia and even China!

I wrote some of my other thoughts here:
https://protonmail.uservoice.com/forums/932836-proton-vpn/suggestions/48175643-double-vpn

Infact, ProtonVPN now take no efforts on obfuscation i believed. Their even using normal api post method to establish the connection on beginning, which can easily been block by government like China. They just need block the DNS query and Boom! You lost connection with Free world. (I check the logs and believed thats the reason we Can’t use Proton in China.Solved easily by take another vpn connection first to cache the Api address DNS records. After TTL, I’ll lost connection if I tried reconnect. ) Proton you are the expert in Tor Why not just leave a bridge for api? Fix Api DNS issues, Bring Free to People……

I vote for it too. I buy 2 years subscription since 2018 and now it makes no sense at all, because my favorite Proton services (VPN, Mail, Wallet, Drive, etc) are no longer work in Russia.

I am not a fighter for the rights, I just want to continue using Proton services as I did for many years.

Other VPN providers solved the issue with censorship resistance, you can do it do, Proton!

Currently Proton VPN doesn't work in Russia. Censorship resistance features may not bypass Chinese Firewall, but it will be enough to bypass Russian government censorship attempts. I'm not sure that precisely technologies described above should be developed to do this, but because some ~1$/month VPNs are able to bypass censorship in Russia, I'm confident that solution exists and that it is easy to implement.
As far as I know, Iran has similar picture with censorship attempts.

Maybe Proton VPN won't help people in China, but it could help people in every other part of the world (if this part has internet access). VPNs can be and some already are a solution to censorship attempts even in countries with worst censorship policies.
I'm not an expert, but I seriously doubt that Iran (or any other country) has firewall similar to China's. If they would've implemented such massive thing it would've be done in Russia in no time. But I never heard of that.

Some other governments trying to test how far they can go with authoritarian policies. Building firewall that great as China has requires a lot of resourses. Russian government trying to do this since mid-2010s, but today they're still nowhere near achieving this. So what governments that go this way do? They implement cheap solutions. Effectiveness of these censorship attempts could be reduced if there are easy to find and to use anti-censorship tools (such as VPNs). By implementing these or similar technologies into Proton VPN Proton helps fight such government policies not only in Russia or Iran, but in all future countries which fell into authoritarian regimes.

Implementing these anti-censorship technologies will also discourage, to some extent, any government in any part of the world from blocking internet access, because there will be another available tool to bypass such censorship policies.

I doubt that ProtonVPN can bypass Iranian or Chinese Firewall.
If you really life in a cencored country Proton won't help a lot with these protocolls.