DNSSEC gives you the ability to verify the DNS response. It doesn’t protect against a straight up packet sniffer or ISP tampering, it just allows you to detect that it has happened.
DoT/DoH are better, they will guarantee you receive the response the resolver wanted you to. And this will prevent ISP-level blocks. But the government can just pressure public resolvers to enact the changes at the public resolver level (as they are now doing in certain European countries).
You can use your own recursive, and this will actually circumvent most censorship (but not hijacking).
Hijacking is actually quite rare. ISPs are usually implementing the blocks at their resolver (or the government is mandating that public resolvers do). To actually block things more predictably, SNI is already very prevalent and generally a better ROI (because you need to have a packet sniffer to do either).
