These 'machines' were not connected to anything. On your laundry day (yeah, you will spend a whole day doing laundry, and not just loading and unloading a machine), you will pull it in your bathroom. Then connect one hose to the faucet, run another into the bathtub. They were absolute crap. Laundromat is a big step up compared to that.

In fact, building the network of government owned laundromats would be better fit for centrally planned economy of the USSR. My guess the only reason it never happened is the inability to build a reliable heavy duty automatic washing machine.

This statement is, again, surprising to me: to connect a washing machine all you really need is water, sink and electricity. I can't imagine a kitchen without these things and indeed, a washing machine was often put in kitchens. The other popular choice was bathroom (my grandmother didn't have one, so they have to use kitchen).

I get it that additional, large appliance may be somewhat unwieldy, but I don't think more than having to haul your clothes to get them washed.