I haven't been a huge fan of Fortnite either but they have become more of a platform than a game at this point, they even have game companies making the different subgames like the people that made Rocket League and Rock Band. I would definitely give it another look.
I looked into Lego Fortnite when it came out because my son is a huge Minecraft fan but I'm totally burned out on it and don't play it anymore. I was shocked with the parental controls and age restrictions that Epic has in Fortnite now ranging from limiting screen time, games they can play, reports, etc. So I have it set up so that he can play Lego Fortnite (Minecraft like), Rocket League, and Festival (Rock Band).
We also just let him start playing Roblox since a ton of his friends play but a lot of the stuff in Roblox is just plain bad, but it seems like there may be ways that people sneak non-kid friendly stuff into it.
He still plays Minecraft more than anything, but I think if he were just starting one of them now, both he and I would probably gravitate more towards Lego Fortnite