It's not exactly poverty, but the 'classist' arguments, to the extent they are rooted in 'wealth distribution' are ridiculous and naive with respect to Constitutional Monarchies.
The 'Head of State' gets a nice home, oh well, it's a drop in the bucket.
That's fundamentally different than some fat oligarch.
BTW Charles will be a fine King. He's nerdy and awkward and everyone loved the beloved Dianna because she was pretty and breezy, which is fine, but I don't believe that 'Instagrammable' qualities are those that fill the role.