That’s what I was trying to say is they have everything they need mechanics-wise built into these game development environments. The difference between AAA and indie is more on the scope of how much artwork, sound design, writing, voice acting, Foley work, etc. goes into the game

A solo independent developer can pretty easily recreate the mechanics of GTA V in Unreal for example, but they can’t realistically recreate a selectively compressed representation of the entire LA and San Bernardino counties plus a 14 hour (or however long it is) single player campaign