You've come to a wrong place to ask. Most people here (judging by recommendations of own VPN instances, Tor, Tailscale/other Wireguard-based VPNs, and Mullvad) don't have any experience with censorship circumvention. Just look for any VPNs that are advertised specifically for China, Russia, or Iran. These are the cutting edge tech, they may not be so privacy-friendly as Mullvad, but they will certainly work.
Hmm. People who recommend widely used approaches, and well-known, well-established providers, "don't have any experience with cenorship circumvention". So the solution is no-name providers using random ad-hoc hackery, chosen according to a criterion more or less custom designed to lead you into watering hole attacks. Right.
1) The problem is very difficult and requires a lot of engineering resources 2) It's very hard to make money in these countries for many reasons, including sanctions or the government restricting payments (Alipay, WeChatPay, etc)
The immediate response would be: "If the problem is so difficult, how can it be solved if not be well-known, well-established providers?"
The answer is simple: the crowdsourcing power of open source combined with billions of people with a huge incentive to get around government blocking.