Why the huge difference in wash times? Is it a difference in the chemical detergents used? Higher pressure spray arms? Are plates and cutlery soaked and/or manually rinsed off first (as opposed to just being "scraped clean")?
1. Commercial machines are designed to do lots of loads throughout the day on short notice, so they heat their water in advance, so it’s always ready to go once preheated. Domestic machines aren’t used that frequently so preheating would be wasteful. (Modern domestic machines even use heat exchangers to recapture heat from the outgoing wash water to warm up the incoming rinse water. Efficient but slow.)
2. Commercial machines prioritize speed over energy efficiency, primarily by using hotter water. Domestic machines are subject to energy efficiency rules that have gotten stricter over time, with the consequence of cycle times getting longer.
3. Commercial machines are designed, in essence, for easily washed items: freshly-soiled, pre-rinsed glasses and dishes (and soaked, if anything was baked on). Domestic machines are designed to do all the soaking and rinsing so that they produce good results even as you collect a load of dishes
and pots and pans over a few days. If you put that load into a commercial machine it’d come out dirty. For restaurants, they make special “pot washer” machines to do pots and pans. A domestic machine has to handle them all.
4. Commercial machines do not dry the dishes at all. “High temperature” commercial machines use water so hot that the dishes flash-dry quickly.
5. Different chemistry using a) a main detergent/degreasing agent for the wash water; and then in the rinse water either: b) in high-temperature machines, a rinse aid so that the dishes flash-dry without spots; or c) in low-temp machines, a sanitizing rinse.