>For bitcoin, it is reached by bringing the cost up. More miners means it gets harder to mine, so it costs more.

I think this is what you meant, but just to clarify: the cost of mining will go up, not the cost of Bitcoin. (Miners joining or leaving shouldn't directly affect the price of Bitcoin. The same number of Bitcoins exist and get minted regardless of the number or activity of miners, as long as it's nonzero anyway, so miner activity doesn't directly affect the supply and demand of Bitcoin.)