Minecraft or Roblox?

I have not played Roblox so much, but from what I have seen of it, it seems to be really polyvalent and low-end PC friendly which makes it really accessible.

However I do prefer Minecraft (even if Java isn't really optimized) mainly because the customization that all the mods made by the community can offer [With Roblox your a bit stuck with a game mode...], and also because of nostalgia ^^'.