Consider a business that has 1000s of customers, considering the high cost of bitcoin transactions these days, would it be better to have just a single destination address to receive bitcoin transactions ( edit: payments ) at, rather than issuing 1000s of unique addresses which is then swiped to a single address later?

The payment can be matched with the user by asking the user to input their sending address before sending (edit: via an UI and storing it in a DB). I would like to understand what the downsides are for such an approach? would you trust the service and provide your bitcoin address?

edit: I understand that the current recommendation one is to use one unique receiving address per user and do a reverse lookup. However I would like to learn what could go wrong with other approaches and why we shouldn't use it.