Mining isn't free. You need to pay for space and power (especially when we're talking about the large scale miners capable of making an impact on the hardware supply). With most bitcoin like coins, the hashrate of the network has diminishing returns as the difficulty increases and the amount of compute resources needed to mine blocks at a decent rate increases. If your computing capabilities are worse than your competitors, it's unlikely you'll make a profit (which is part of why bitcoin mining is the land of ASICs these days, gpu/cpu mining of bitcoin doesn't happen, most gpu miners mine ethereum or monero, then if they want bitcoin sell that and buy bitcoin).