It’s not really about 24/7, but it is about quality of components. Enterprise gear is made using slightly better parts and tighter tolerances. Things like more expensive capacitors rated for more hours/cycles, better power filters, things like that.

The end result (and this is easily verified) is the failure rate is much, much lower than comparable consumer-grade equipment.

There is sometimes a blurry line between what counts as enterprise vs pro-sumer vs consumer gear, though.