A problem here is that UUIDs are not actually a silver bullet against collision. You will never generate a UUID that will collide with someone else's, but it is

A problem here is that UUIDs are not actually a silver bullet against collision. You will never generate a UUID that will collide with someone else's, but it is easy for someone else to collide with you, either on purpose or because they made changes to data from your platform before sending it back (PKs tend to leak in URLs, APIs, data exports, etc). I find that I have to implement a system for re-numbering incoming data on migration/import anyway, so the advantage of UUIDs is not that huge.