Network effect / moat / unique offering?

I think I understand the premise of this stock, even if I don't relate to it or subscribe - credit cards are going away, and this is the future of short term financing that drives consumption.

My question is whether there's any significant first mover advantage here other than branding. Once I'm a user of Afterpay, it seems very easy to switch to another provider who does the same thing. Once I'm a retailer I could similarly switch to another provider. There's a network effect in that retailers want the BNPL system with the most users, and users want the system with the most retailers - but given that there's very little reason that users can't have multiple systems (most obvious being Apple, Google, Samsung, banks, Paypal, Visa/Mastercard, Facebook, Venmo/Zelle, the list goes on) not to mention cryptocurrency and whatever else... where's the value? Retailers will surely support any payment ecosystem that has a moderate user base, there's no reason not to, and there won't be any 'Coke or Pepsi' type exclusivity deals allowed.

It seems like this is the bet for APT - that users will stick with the product even in the face of alternatives with very little friction. Is this a risk?