Except players do have to manage the rules. They have to know what spells they can and can't use going in. They learn this from their Player Handbooks, and other resources that are available. It's not like a rules lawyer is limited to a subclass of GM. This isn't just 5e, it's DnD in a nutshell. It's amazing to me that you have access to all these resources, and yet, don't use them to enhance your DnD experience on the PC?
The point is that they want the game to set these rules for them, the same way it sets any other number of rules, so they don't have to look it up themselves. The game could easily be written to automate that.
