Single axle good or bad depends on the weight and axle/tire ratings. Lots of times (as in my case), the manufacturer will equip a 3000 lb (dry) trailer with 3500 lb axle/tires, so it's easy to go to the max or more when loaded, especially if you boondock and need to carry water.
I swapped in a 5200 lb axle and tires rated for even more, and now don't worry about blowouts. 10K miles so far without any issues.
In the past, had a pop-up with small tires, took it on a summer 12K trip, 4-5 blowouts. No issue other than the hassle of getting another tire. Finally figured out that load range E tires were the way to go, although harder to find in 20.5x8x10. (Jayco put LR C on it).