I've made these sorts of arguments before.
Historically money has had a huge network effect, because exchanging it has been impractical, inconvenient, or expensive. With crypto-to-crypto exchanges (including those built into payment networks you mention), this is no longer the case.
There is still some network effect, but it seems much smaller than before, and this may well lead to a different outcome
I actually HOPE I'm wrong, coz having coins dominate for reasons other than tech superiority is depressing, but that's what history shows. Advertising is extremely powerful.
One example to illustrate this power, In my country after shave 'Old Spice' got a big sales boost after a TV add from another country went viral on the internet - https://www.youtube.com/watch?v=owGykVbfgUE - usage boost of over 25%, and that add didn't even show in my country on TV.
IMO one of the biggest factors that will decide which version of which code base is successful 'could' come down to who makes the best funny add that goes viral. That's probably a bigger factor than blockchain bloat, anon, or even transaction speed. Who makes the best TV advert.
It's kind of separate issues as to: 1) whether it becomes a winner-take-all (or close) market; and 2) if so, what determines the winner. If it does turn into WTA then I also agree with you that technical superiority (if that is even objectively meaningful) is very unlikely to determine the winner.