Cryptos are not companies, and even if they were, they are open source. Name two open source projects that compete with each other. There are hundreds of versions of Linux. Hundreds. Imagine there being hundreds of versions of windows or OSX. That kind of diversification simply does not happen with centralized projects.
How can two open source projects compete with each other when both sides can use the code of the other? We are trained to think in terms of competition and zero-sum gain/loss, but this is not how open source projects work.
Read the link in the OP for more info.