Hot and neutral wires are usually separated by about 4 to 6 inches, so they can dissipate heat faster and handle slightly higher amperage
There is also a gap between panel surfaces and the wires, so they’re less likely to be damaged by nails
Installing knob and tube wiring requires a fair amount of skill and experience, so the quality of workmanship was usually well above what we have nowadays
The ceramic components don’t age, so the installations have a nearly unlimited lifespan (unless they break)