You VASTLY underestimate first mover advantage.
For the first mover advantage to have importance in technological fields, it has to have technological superiority, control of resources or high user switching costs.
As I see it:
1) Bitcoin is technologically inferior.
2) Bitcoin isn't the sole representation of this specific idea or technology.
3) Switching costs would be trivial for services and users to switch to new cryptos.
Oh, nice, bullet points!
1. No, bitcoin is developed by hundreds of actual developers who create amazing features not present anywhere else, while deploying it on a live billion-dollar value blockchain while keeping it secure; most other cryptos are just copies by get-rich-quick kiddies who have no idea what they are doing.
2. That is true; same can be said about IPv4 but it still rides along for 30 years.
3. Oh no, most of the infrastructure already assumes bitcoin, promotes bitcoin, uses bitcoin. Of course, everything can be switched theoretically, but not "trivial", and sometimes even impossible, for example for the hashing network. Which is, regardless of what you say, the greatest strength of bitcoin.