If the ISP (or Nation) is willing to block google or cloudflare IP-ranges then you will have to be a moving target.
Using tor and similar. For normal shitty ISPs thats not an option
Cloudflare and Google's dns resolvers got a lot of adoption bc they provided a way for normal people to get around censorship, but they're inherently censorable bc they're run by centralized companies. There are new initiatives aiming to create a distributed dns layer which are promising like https://handshake.org.
And the distributed DNS layer will get censored soon enough if it gets traction. If you need proof, look at how TOR is doing in china.
Security is not binary, it's a spectrum based on cost. It's the same for censorship-resistance. If Handshake increases the cost of internet censorship for every country in the world, then it will have succeeded even if it's still possible for countries like China to censor it.