Why would someone mine a crypto with less dollar value when they could mine a crypto with a higher dollar value, bearing in mind they're going to sell it immedi

Why would someone mine a crypto with less dollar value when they could mine a crypto with a higher dollar value, bearing in mind they're going to sell it immediately? Blockchains are like Highlander. There can only be one. The more people mine one, the less miners are available for others. Satoshi already proved this.