The idea is that a simple "like Stripe, but better" doesn't cut it, you need to define "better", which then becomes what makes you NOT Stripe. And it's not too late if you can figure out how to do something that they don't do. In the spirit of the article, find a schlep they didn't tackle: availability, pricing, payment devices, support for legal revenue tax evasion strategies... :) whatever.
Because there's already a Stripe. Doesn't mean you couldn't start a company to do what Stripe does, but it'd be hard, since people would probably be saying, "Isn't that what Stripe does?"
I disagree completely. Stripe is the only one so far who doesn't suck. There's room for more, and plenty of room for differentiation. Sure, stripe.com set the bar and has first mover advantage etc., but that doesn't mean they now own the market. Not at all.
If you did exactly what Stripe did but charged less, there is no reason you couldn't completely replace Stripe. You aren't being judged on novelty here.
