I’ve found DDG to be adequate for the majority of things I search, but when I need something specific or with some nuance, it fails miserably. For that reason I still use Google when I do stuff for work, or when I do troubleshooting. For my daily usage DDG is just fine, though.
I wouldn’t mind doing it. I run my own DNS so it wouldn’t affect me, but I figure if they’re already trying 8.8.8.8 they may as well try 8.8.4.4 and perhaps more, so it’d require a bunch of firewall rules.
Now, all of that is moot point cause I hate the whole “smart TV” thing, so they’d never be connected to the internet.