Stripe charges 2.9% + 30c per transaction.
From that, about 1.3% + 5c per tx go to interchange + assessment fees.
This leaves about 1.6% + 25c for the payment processor.
14.3 on 816b is about 1.7% which is consistent.
On 1T, that means about 17b in revenue.
Lets assume they have 7000 employees (i've seen 6000-8000 in searches). As rough estimates, these SFO-based SWEs + knowledge workers cost 1m/yr on average (which includes their total comp, insurance, federal + state taxes, and operating overheads amortized over all employees). So their cost of labor may be around 7-8b/year.
They may have other acquisition and marketing costs, but it means the co can feasibly be earning >8b before taxes, depreciation, amortization, etc.
That number could justify a 80b valuation.
If their current round cap is 55b, then my #s on costs are off, or the multiple has dropped to 6-7. Please debug.