My nephews were into it. I tried to play with them and there were not a ton of real games. Some fun like driving maps people had made just to crash and jump ramps, some shooting gallery things. The thing that concerned me was the amount of games that were obvious gambling type stimulation. Games where you do nothing but collect coins or points to get a shot at a pet or piece of loot, but then block access after a few free hits with a timed wall that could be removed for robux.

The other thing that concerned me was the amount of adults there just to 'play' i joined a shooting 'game' (just a bunch of stuff to shoot and guns laying around) and there was voice chat included and some guy with an eastern european accent making homophobic jokes and talking about how someone should add lazy mexicans as targets. Not uncommon online, but roblox I had at one time thought was trying to be a childrens platform, boy was I wrong.

I let my SIL know she might want to keep them off that or be present whenever they play. She did not listen until one of my nephews stole her credit card and used it to buy a bunch of crap online.

You didnt understand something... so you banned it?

It's basically a pipeline for every possible bad thing that could happen to your child. I'm glad you got rid of it