It's really surprising this can go unchecked: 1) it makes the cost of acquiring users artificially high, since its an expense that doesn't lead to a completed

It's really surprising this can go unchecked: 1) it makes the cost of acquiring users artificially high, since its an expense that doesn't lead to a completed signup 2) you'd think the verification process would be monitored anyway, in case of deliverability issues or false negatives on checking the codes - even if not spikey because this was always happening, surely the high baseline 'code requested and never entered' would raise questions?