In the US, yes (in most cases PayPal is legally a money transmitter), but as sibling comment pointed out this is not necessarily the case in other countries with stricter legislation.
You would be shocked how big seemingly small tech companies get as they grow/age. For example, you might start your site off by spending a week building a billing integration with Stripe. Ten years later, you have 10 engineers, 3 PMs, and a designer, and 20 operations people on a billing team, plus managers and directors for everyone.
Plus all the KYC, support, fraud, and infrastructure to support all those roles.
You wouldn't know it based on how terrible their support is, but that 28k number doesn't shock me.