[Si Coe]

Shafts are a little more robust, but have the downside of having more torquesteer.
Touring cars are now pretty much exclusively belt having gone through a brief phase of shaft drive. Strength isn't that big an issue, but the belt cars have notably better handling.
In contrast 1/8th off road is exclusively shaft drive. The power of the engines means the durable shaft is a lot better and they are heavy enough that torque effects from the drivetrain are not significant.

Now the thing is in 10th off road we sit kinda halfway between touring and 1/8th off road, which means that in practice either system works effectively.