replacement motherboard (ludicrous this is this even a thing

A lot of energy and water savings in modern machines are due to the electronics used. Also, replacement of weight to keep the machine from wandering around during spin cycles with sensors and attempts to rebalance laundry, if necessary.

was triple the price of the entire washing machine.

The EU commission is aware of that, though for now hopes their ecodesign initiative for repairable products will be enough to push vendors in the right direction. Given that all of this is pretty new it's quite impressive to see how some vendors are embracing it already - I first noticed it when replacing an ancient kitchen oven, and in the shop next to spare sheets I could get all electronic components used in that thing.

I imagine they'll monitor the situation, and will have a chat with problematic companies based on that, or consumer protection complaints - like they did with the switch joycon drift thing, which I think was one of the first instances where eco design was referenced as reason for taking action.