A card-only checkout doesn't just add friction for underbanked or privacy-conscious consumers — it eliminates the sale entirely. Cash alternatives like checks, escrow, and money orders convert exactly the segment a card-only flow can't reach at all.
What this actually recovers
These aren't buyers choosing a slower payment method out of preference over a card — for a real share of them, it's the only payment method they're willing or able to use online. Offering it is closer to opening a new customer segment than optimizing an existing one.
The cost of that conversion
The tradeoff is real: payment collection delays, bad-check risk, and a meaningfully higher chance of abandonment mid-process compared to an instant card authorization. That's the price of reaching a segment a faster checkout simply can't convert.