I have to admit this is a bit of a monstrosity. Fortunately, the road is on the uphill side of the house and the incredible height of the deck will rarely be observed.
Some design critiques (I didn’t design this deck, but I built it):
The enclosed area should have matched the width of the house and not enclosed the stairs. The cube of the house should have continued under the deck. The stairs are separate and enclosing them doesn’t help anything.
Also, The enclosed area should have gone to ALL of the edges of the deck, including the area with the angles. It should look like a big volume with a deck on top, not a deck with some part of it enclosed. It would have taken a little more effort (and money) to match those angles, but that’s what it needed. The choice becomes: Add the angles and pay for it, or keep the corners square and save money, but either way, the enclosed area is under the whole deck, not just part of it.
There is one good thing about all the volume beneath the deck, contained with all of that cedar: Storage.
There are barn doors on the opposite side of the deck so the owners have a secure storage space. It will be a long time before they have enough garden tools to fill up that space. They could probably rent it out on Air BnB during South by Southwest.