Indeed. Essentially, the resources available to the average person are sum_of_all_resources / total_nr_of_people. The amount of a lot of resources (energy, food, mobility, communication) to go around has grown greatly since the industrial revolution. But some resources, like land, minerals, fish in the sea, are just fundamentally limited. The only way to have more on average is to diverse what is available by less people.

Or you can just take more for yourself by stealing it from the less privileged and future generations, which seems to be the current modus operandi...