I don't think the area under the cabinet was intended for the washer/dryer. It looks like they just built some storage that could be utilized next to the machines. You can have a flat piece of wood installed to extend the cabinet face so it isn't an open area that can't be cleaned.
If you replace the washer dryer with front loaders, you could put a countertop over the machines and run it around the corner over the cabinets if those were rebuilt. Maybe all you need to do though is just look at the cabinet area. If you removed the upper cabinets and moved your hanging pole there it would be a much more functional space. Depending on how much hanging you do, you might want one upper cabinet and the rest hanging area, or hanging with a shelf like this example. Be really careful to get a licensed contractor from someone you know personally if you're wanting to make big changes. There are a lot of terrible contractors with fake reviews online in this area.
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Landry closet door idea
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