I find a percentage of total calories to be an interesting way of looking at it. Any changes you make to one macro affect one or two of the other macro percentages. When you think of it this way, the macro ranges you are talking about come into focus. If you are eating 500g of protein and eating 4k total calories, you are getting 50% of your calories from protein. This might be fine but it only leaves 50% left over for fat and carbs. I don't know if you've ever eaten only 20% of your calories from fat but most people who try it get issues from too little fat, I find 25% to 30% of calories from fat to be perfect, some might want to go a little higher or lower, but not much. This only leaves 20-30% for carbs. Now carbs are protein-sparing and anabolic themselves, muscle size is a good portion stored glycogen (around a third of their size in untrained individuals).
So you can see, if you are eating 4k calories (which is a lot) or less, eating 500g of protein at 30% fat intake will only leave 20% for carbs and that won't be ideal for most.
Now if you are eating 5k total calories, eating 500g protein starts to look a lot more realistic, this is 40% of your total calories, leaving 20-30% for fat and 30-40% for carbs.
If you are like me, and you 230lbs and eating 3k calories (my metabolism isn't super high at and I'm doing a little recomp) eating 500g of protein would be 2/3rds of my total calories and I'd have to eat so little fat and carbs it wouldn't work at all.
With the exception of some very specific diets and people, almost everyone is going to need fairly 'cookie cutter' macros: Protein will be in the 25-45% of total calories range, carbs will be in the 25-45% range, and fat will be in the 25-35% range. If you try diets outside those ranges, you will usually run to some reason to change it fairly quickly.