Yep, I bought a separate all-in-one computer that is in the living room, in full view of everyone else, so we can keep an eye on what is going on when they are using it.
We also have pi-hole running that blocks a lot of things, and can turn on and off certain domains (so they can play roblox etc for a short while, then its blocked again) and their devices are pretty locked down
All four of my daughters prohibit my 7 grandchildren from going anywhere near roblox. My grandchildren are currently ages 2-11 but my daughters are so outraged by what happens there that they say their children will never be allowed on roblox until they move out of the house. Apparently it is extremely predatory, lots of bullying, and highly sexualized - and while children are the site's target audience, the site provides no effective oversight.
We also have pi-hole running that blocks a lot of things, and can turn on and off certain domains (so they can play roblox etc for a short while, then its blocked again) and their devices are pretty locked down