In my experience most vendors will just cancel/pause your account in the event of a failed transaction, unless it is for a very large amount (>$50) they wont bother sending it to collections because there are fees for them to do that.
In my opinion the best benefits of privacy.com is that you can provide a fake name and address during signup (they will authorize it with any name/zip/addr). Good luck sending stuff to collections without my real name or address.
Mercury.com also provides a similar virtual card service to business banking customers, but unfortunately they don't let you use fake names/addresses like Privacy.com does (probably for good legal reason).