Yep, before this heads fore the bilges, if you're not braked then the number of things that can go wrong (i.e the brakes!) are well reduced.
Nos' list is pretty exhaustive.
To put it in perspective, my Snipe Dinghy trailer is still going strong on the bearings it came with in 1986 (and no idea how ling they'd been going before that). The suspension units are now on their way out, but the bearings just keep rolling....... My box trailer has had one set of bearings in about 20 years, it's on old Mini Hubs with taper rollers.
Moral of the story- if you keep them lubed, they'll keep turning.
Oh, and the comments about flushing systems are also irrelevant, as there's nothing to flush!