Prelude

Not to be racist, but it's a fact that a high % of Chinese owned restaurant do everything they can do minimize the cost, like pull the plug of the chemical.  $800 a month for chemical is not cheap, the restaurant needs to sell around 800 drinks a month JUST to cover the chemical cost of WASHING the glasses.  And there are many other costs too.

Prelude

Back to the topic, the glasswashers are designed to be quick reuse, like 1 minute and it's lower temp.  Diskwasher is higher temp, and takes longer to process.

The speed is important, because restaurants don't have enough glasses and wine glasses for turn over tables and reorder drinks for every seat.