Is it?
I'm on my second iPhone 13 mini, this one being the replacement after the first died of a drop. There are two more stored in the attic, each preconfigured with the accessories I like and with a SIM from my provider in the box. So if anything happens to this phone, as soon as I get home I just break out #3, restore the latest backup, activate the SIM and assign it the number, and I'm back in business at the same old stand.
An iPhone 13 mini with the accessories I like (case and charging adapter) is about $300. That's amply worth it to me, a couple times over, to never have to think about how to replace a cooked phone and get back into communication with my family and the world. Nothing special about the phone, it's if anything unusually unassuming. It's just the phone I happen to like (since 2021 when I concluded it no longer made sense to keep keeping 1st gen SEs alive) and thinking about phones is something I only like doing when I want to. That's the problem this money solves, and I have the money available to use this way, so why not?
Scale the dollar amount up a few orders of magnitude and the necessity down by the same amount, and sure, I see how it makes sense to "just" drop an identical set of wheels at every one of your pieds-à-terre. What did the funny sweary smoking man in the movie say? "You learn to spend what's in your pocket."