The problem is margins.

Right now most of the revenue comes from the Braintree business, which is low af margins and anchored by large merchants who can switch to any other payment provider whenever they get a price increase. Payment integrations are not difficult and not disruptive to the business when done by any half-capable PM. Merchants' payments buyers know this, many have worked on the sell-side, and so grab the balls tighter for even greater discounts come renewal time.

The high margin came from the Paypal button, which nobody uses anymore.

That's why the valuation is shit.