Why are DW so complex?

[Chetlaham]

I mean picture DW tub. Why not have a cylindrical sump, cylindrical pull-out fine filter, two hanning pumps, and of course hoses to inter connect them to the sump and one to the spray arm hub. Simple one at a time fill on, wash pump on, drain pump on repeat. Why go through trouble of giant disk shaped sumps and complex pump sequences?

Hannying pump:

https://www.repairclinic.com/PartDetail/Drain-Pump/WH23X10030/3015301