How witness descriptions work
To really get why changing clothes is so powerful now, you have to look at how the witnesses behave. When an NPC calls the cops on you, they aren't just giving them your exact GPS coordinates anymore. They are giving dispatch a physical description. If Jason is wearing a neon pink tank top and a hockey mask, that is exactly what the cops will be looking for when they arrive on the scene.
Breaking the profile
If things get too hot and you manage to break line of sight, the cops will be actively scanning the crowds for someone matching your exact description. This is where the magic happens.
If you can sneak into a clothing store, or grab a new outfit from the trunk of your car (which is a feature a lot of people think is returning), you completely invalidate that witness report. You can literally walk out the front door in a business suit and the cops might drive right past you because you don't look anything like the guy they are looking for.
Masks are your best friend
Just like in Red Dead Redemption 2 and the big heists in GTA 5, wearing a mask is going to save your life. If you put a bandana over your face before you rob a gas station, the cameras and the witnesses never see your actual face. When you run around the corner and take the mask off, you instantly shed the most obvious part of your suspect profile.
I wouldn't be surprised if the game lets us equip and remove hats and sunglasses right from an interaction menu just so we can quickly change up our look while running down an alleyway.