Because this isn’t for individuals. Corporations rent houses like this. Movie studios, music labels, executive perks for the c suite, and more recently YouTube streamer companies. When you have clients that need to travel a lot it’s offered as a perk for them to “live” in one of these fancy houses. Executives who only stay with companies for a few years are easier to recruit if they don’t have to hassle with buying or selling a home during a relocation. Or in the modern times YouTubers who need to a fancy house to stream from for content.

Rental costs are expenses, owning is a taxable asset.