That's not the case anymore. They built an application level filter. For example, Wikipedia block was due to http header reading. https wasn't also a solution because of hand-shaking part. Even TOR can be blocked this way but it's reachable through obfs4proxy.

Besides that, DNS queries to all servers are blocked if you try to get a blocked site's IP. No hijacking attempt here, as far as I can see.

I routed only Wikipedia through TOR with a browser extension. With this setup not all DNS queries goes through proxy. So I had to take advantage of CoreDNS' dns-over-tls support.

Because people who knows basic networking and also read English are less than a thousandth of the country, their method works very well enough.