I've ran Pihole for years but switched to NextDNS. It gives me more control over my kids access.
For example scheduled access to YouTube and Roblox. Also, since it's a public service it means I can block them regardless of network. So for example when we are on holiday. My eldest worked out he could use network data on his phone to avoid the Pihole.
Oh, and it's DNS over TLS so queries are now encrypted rather than plain text that regular DNS.
None of this will block YouTube ads though. For that I use NewPipe or Firefox and uBlock Origin.
They find ways yes. When I was blocking YouTube I found him watching YouTube via Spotify. Not sure how that worked. But I blocked that too as a result.
I don't think they have anything currently as when it's blocked you see them outside their bedrooms a lot more!
My mom disabled the browser on my phone, so I hit the button in an app to view the terms of service when then opened up an in-app browser. When she figured out how to stop that, I manually typed out the url for a google search and downloaded the webpage using shortcuts on an iphone, then hopped around the internet by downloading and viewing the webpages of any links I could find. Surprisingly, it worked on things like YouTube as well
On the bright side, stuff like that is why I'm far more computer literate than many other people around my age that aren't in college for something IT related
That's the point yes. At some point I'm sure they will work it out. But they haven't yet. Luckily the eldest is lazy. If he wasn't he would have read the email he got when he was 13 which meant he could leave the family group which I also use to turn off their devices for bed time...