It’s a bit much to say it’s a terrible idea. Not everyone wants to or is able to run their own DNS sinkhole, and some would rather just outsource it, which is fine as long as they understand the compromises and risks.

I do this, too. I used to run a Pi-hole at home, but I’ve been too lazy to recreate it and make it accessible both at home and away.

More-or-less it’s Pi-hole as a service: https://nextdns.io/