Saying Afterpay is nothing more than a credit warehousing facility and a phone app and because of that there is no barriers to entry tells me you know nothing about providing software that is secure and scales.
Easy/quick to develop, secure, can scale to millions of users. pick any two. All three is impossible. The barrier to entry is higher than you suggest.
APT Price at posting:
$86.47 Sentiment: Buy Disclosure: Held
