I haven't used them (and I despise Roblox) but my understanding is that the Roblox creation tools are actually pretty good.

I have some kids into editing Roblox, and I'm a full time Unity / Unreal dev, and I would say that the Roblox editor and engine _are_ really good.

Kids don't care about fancy graphics, they care about connecting and running around with their friends, in a wide variety of games, that are downloaded and up and running within seconds.