I thought dusting my collection was bad...
Ditto that... I had 4 JYSK double door Detolf style display cases. Dusting them all the time wasn't fun, felt more like a chore. Most of my stuff back then was carded and loose 5 3/4" figures. Over the years I got tired of it til I ended up moving and packed them away in storage.
This glass display house appears quite high-end... I'm guessing the owner has a hired maid/butler to go cleaning the glass and dusting all the contents... Or unless there's a very high-end air filtration system built in for the central house, if not a seperate one built into the display cabinets to continually cycle continously filtered air. Majority of those floor to ceiling display cases looks like hinged glass doors, same idea as a Detolf.
But hey, everyone has their own preference to collecting and displaying their collectables. Some people collect toys, coins, stamps, plates/dishes, decorative spoons, salt & pepper shaker ornaments (my grandmother was big into that one with wooden wall hangers), antiques (insert antique collection whatever type/range here), dolls, china dolls, sports cards, comics, guitars, automobiles, real and/or replica movie props etc... Those of us here on the forums collect figurines anywheres from ~4" - lifesize scale and its all cool