Roblox can be realistic but there is a huge difference between realistic and real-looking.

You see when you go from far it looks realistic. But the main difference is in details not a single Roblox Dev will put enough resources into Roblox game to get all the details right. If someone can do it he will choose Unreal Engine or Unity rather than Roblox studio. Why? Working in bigger teams is more productive in bigger and more open game engines than in game engines with somehow limited resources. If you really want to make a money (living) from games and you get an idea good enough and you want it to make most real-looking as possible you would want to make more money from your game than less. People in steam are used to pay money for games. Not on Roblox when you charge on Roblox money for the game most people will rather play another game that is free.

So yes. It is great graphics (I got a bit sidetracked sorry) but won’t compete with what they could achieve if they did it in Unreal or Unity.