Tesco's last generation machines are particularly bad, although their newest ones have removed a huge amount of latency from the UI and weighing scales from what I've seen.
If you're shopping for a single item, scanning it and dropping it in the bagging area is sufficient to start the flow, then simply wait a second, click finish, then tap your contactless card is all required to complete a transaction, can be done in under 5 seconds
The best machines I've seen in the UK in terms of user flow are probably at Waitrose, they're just supremely faster to use than those at Tesco
If you're shopping for a single item, scanning it and dropping it in the bagging area is sufficient to start the flow, then simply wait a second, click finish, then tap your contactless card is all required to complete a transaction, can be done in under 5 seconds
The best machines I've seen in the UK in terms of user flow are probably at Waitrose, they're just supremely faster to use than those at Tesco