I recall reading that when the costs of distribution (but not the costs of discoverability) are low, generally you end up with a power law sort of distribution of consumers to providers, where provider #1 has exponentially more market share than provider #2 and provider #2 has exponentially more market share than provider #3, #4, etc.

Examples of this are Windows/Mac, McDonalds/Burger King, Playstation/Xbox, Nvidia/?, AWS/Azure?, Android/iPhone, etc...

Basically, the majority of users all using the same dependency/platform/product is basic economics.