What is the difference between that and a locked door not opening up unless you have the key?Well they don't really either but they can do. RPGs by default will never allow you to have full freedom while adventure games might. You're never going to get the excellence of BOTW in an RPG.
You have freedom but that freedom only means you have the potential to do things, not that those things don't require prior planning/setup.
I don't really like a lot of rpg systems but I've never thought of adventure games having more freedom.
If you hadn't noticed, this is Forum 2.0