They take clearly too little water.
They take it clearly too slowly.
They idle far too much at the beginning.
They idle far too much at the end.
They do not offer fast forward capability like mechanical machines did.
They do not show their current status like mechanical machines did.
They’re often broken like mechanical machines were.
They make it unclear which programs have pre-wash and which don’t.
They make everything else pretty unclear too, like what a particular button does.
An ideal washing machine:
Large intake hose (or two if it is a model that takes warm water too where district heating or wood heating is available). When the user presses start, the machine starts taking water at full speed at that precise microsecond, unless it is gauging the weight of the laundry.
Laundry weighing will be done in a few spins, after which water intake commences with no delay.
A display shows the state of the machine. At least the following states are displayable: pre-wash, wash, rinse, spin.
A fast forward mechanism moves the machine to the next state.
A stop mechanism stops the machine in any state.
After the laundry is spun, the machine can spin slowly and reverse a few times to unstick the clothes from the drum walls, but this can be stopped and the laundry removed from the drum immediately.
The spin is braked so it doesn’t take minutes to coast down.
The temperature of the wash can be changed even if the program or wash has already started without having to reset or flush.
The spin cycle can be enabled or disabled even if the program or spin has already started without having to reset or flush.
Extra water can be enabled in the middle of the program.
All this was possible with seventies mechanical logic industrial washing machines. Note that almost all of it is pure logic whose cost is pretty much exactly zero once you’ve developed it, and other things like large hoses are trivial improvements.
If you will use this specification when designing a washing machine, then send me a machine: I will test it and say what improvements still have to be made.