>>2058024But they are? Mostly.
Every civ gets food from berries, deer, boars, farms, fish.
Every civ gets wood from tree clusters or lone trees..
Every civ gets gold from gold mines on the map, traders/pilgrims, relics, sacred sites, trade ships.
Every civ gets stone from stone mines.
Every civ can use the market to buy/sell resources.
Then there's also some map-dependent special sites every civ can access, e.g. the merchant camp for 1 villager's worth of food+wood+gold, the ruin for stone and potentially a relic, and fish.
That's the fundament built upon for every single civ, with slight tweaks per civ like how Muslim civs can't harvest boars but get more from berries, or how the Byzantines get a fifth bonus resource as a side product of harvesting berries or their farm variant that they can use to hire mercenaries.
But why would you even want everything to be the same? You should want more differences because that widens the range of available strategies. And that's one of the things that RTS are about, choosing and executing those strategies... in real time.
I actually think that in practice, the option to have infinite resources also increases the range of available strategies, because it's not always the best thing to go for, contrary to what the term "infinite" might insinuate. But it's one more option that may make sense, based on the game state and timing.