That game already exists. Intel and Amd had an odd relationship for years when Intel needed Amd so they could claim that competition existed. Cross licensing instruction sets and the like.

That would have interesting implications. Companies would have to grow by aggressive diversification into other markets. Instead of a Google or Appple that controls your digital life, you'd have an endgame with a few ACMEs that attempt to lock you in in every aspect of your life: Your pots would work best with a stove from the same company. Your washing machine and detergent only do a good on a specific brand of clothes etc. A completely different kind of market regulation would be required.