ISP rarely do anything else than DNS censoring (censoring by ip blackholing is for really grave stuff). Also i don't understand why you'd be "better off" using encrypted connection to a 3rd party DNS which can still lie to you. Just run a local resolver, it's so lightweight there's no real reason not to. (and honestly, the hypothetical delay isn't noticeable)

Sorry, am I missing something because I'm pretty sure the whole point of the article is that ISPs do block more than just DNS

Is it? I didn't understand that. It's just a random tutorial on using a proxy for a specific domain.

A 3rd party is better because it can be hosted in some other country not subject to local fascism du jour you have to deal with from your ISP.