Cool chart:
h/t x.com/TristanBietsch
Discussion
BTC transfer speed is around 1 hour (6 blocks) to guarantee it didn't orphan.
it depends on your security parameters. I think bitcoin has about 1 block get orphaned per day; so if you wait for just 1 confirmation, you have a 1/144 chance of it getting orphaned, which is probably fine for many use cases.
Moreover, even if it *does* get orphaned, the *replacement block* is likely to include almost an identical set of transactions as the orphaned block, because most miners use the same template and so they include the same transactions in their blocks.
So even if you're very unlucky and hit the 1 in 144 chance of getting orphaned, you'd have to be in the "unlucky jackpot" to *ALSO* get in a situation where the replacement block doesn't contain your transaction.
Most importantly, scarcity.