Properly fletched "stick-on" vanes, Spinwing style, do not randomly come off if they are shot from a bow that is properly set up and tuned. They can be damaged by shooting tight groups, shooting through the clicker, or shooting into brush, but not just randomly.
The advantage over glue-on vanes is that Spinwing style vanes tend to be:
- Lighter
- More flexible
- Curved and with a built-in offset angle (depending on the exact kind of vane)
- And yes, easier to repair in the field
Points 1-3 mean better clearance for a proper tune and better performance for the slower speeds that recurves shoot compared to compounds.