Hi Milkii, Quest (2) can be used in two modes - standalone or linked to PC. When standalone, it uses its internal hardware (processor, graphics…) for all apps, including VRChat. When in link mode (connected to a PC) it uses your PCs hardware, which typically means better performance since PC usually has better processor and GPU. From the perspective of VRChat, it will register you as a ‘Quest User’ when you are in standalone mode and in that case you will be limited to Quest worlds and avatars. But when linked to a PC you will have access to everything, just like you do when running VRChat from your computer.
My experience with Quest (ver. 1) linked to a PC is really good and I expect Quest 2 should be likewise if not even better. Quest 2 is by far the most versatile and best buy VR headset you can get today IMO.