Laundry room questions

Kind of a random subject here, but I am gearing up to build out a laundry room. This is my first washer and dryer – always lived in apartments until now. I want to do a nice space with built-in cabinetry surrounding the W/D, but I don’t understand how that works with service and maintenance. I have stacked units, and together it/they way a ton. They’re also located in a nook where the floor is raised about 1.5″ from the surrounding floor. It just seems like it’d be at the very least quite difficult to pull the whole thing straight out enough to access whatever’s on the back side if it’s up against cabinets. And does that really work for the vent? Is there really enough give, even with a flex duct, to pull it out that far? Aren’t I supposed to clean out the vent somewhat often? Sorry for the ramble deep into a random subject – just see all those pretty pictures of laundry rooms where it looks like the machines are basically built in, and can’t get my brain around how that works. Thanks!