Requiring shoppers to create an account before completing a purchase costs sales at a rate few retailers measure. The mechanism is about timing rather than about the effort involved.
The request interrupts a completed decision
By checkout, the shopper has chosen the item and intends to pay. Any new requirement at that point is an obstacle between a decision and its execution.
Account creation asks for effort in exchange for a benefit that accrues later and mostly to the retailer, which is a poor bargain at that moment.
Which means a meaningful share of shoppers abandon rather than comply, and they abandon holding a basket they had already committed to.
Password friction is worse than the form
The form itself is short. The real cost is that many returning shoppers already have an account, cannot remember the password, and enter a recovery flow that leaves the site.
Password reset routes the shopper to an email inbox, which is the most distracting environment available and one many never return from.
Guest checkout avoids the entire branch, and offering account creation after the order is placed captures most of the same data with none of the risk.
Mobile amplifies every step
On a phone, each additional field is more typing on a smaller target with more opportunity for error, and error messages often scroll out of view.
Autofill and platform payment methods bypass much of this, which is why enabling them typically moves conversion more than any redesign of the form.
Retailers that support those methods find the effect concentrated on mobile, where the friction being removed was largest.
What the account was actually for
The usual justification is that accounts enable order history, faster repeat purchase and marketing contact. All three are legitimate and none require the account before payment.
Order history can be attached to an email address, and repeat purchase convenience matters only to shoppers who return, who are a subset.
Treating account creation as a post-purchase offer rather than a precondition keeps the benefit and removes the cost.
Why it survives despite the evidence
Account creation rates are reported as a success measure in many organizations, so removing the requirement looks like a decline on a metric someone is accountable for.
The lost orders, by contrast, never appear anywhere, since an abandoned cart leaves no record of the sale that did not happen.
That asymmetry in visibility is why the requirement persists in places where a straightforward test would have removed it years ago.