Think about the reasons to get a boat in the first place.
Sure, if it's just an expedient trip down river, 'find another way' is an option, but if you're going to an island, crossing a huge body, or basically any other reason to get on the guaranteed date with the worst combat experience in D&D - aquatic combat - you're going to need another boat.
This is essentially the same problem as when the Dm or adventure sets up having to pass a skill check to find a piece of evidence or signpost to advance the plot and then that check is failed: it's having a chance of failure when there's not only no good reason to include the possibility of failure, but failure results in stalling things.
Ultimately, the balance of having a meaningless check for 'realism' vs having a character moment and improv opportunity in explaining the implementation of the background that lets the PC get that passage without that check seems pretty obvious to me.