You can pretty much say the exact same thing about stealing someone's wallet or purse. There's a lot of travel advice to the effect of "don't keep everything in one place". A phone is no different.
A phone at least has the benefit of being backed up. In theory, I could log into a couple accounts on a brand new phone and have access to everything within tens of minutes. Contrast to the hours of phone calls and weeks of waiting it takes if I lost my driver's license, passport, etc.
And though a phone can be used for payments, it must be unlocked. Not true of the physical credit/debit cards (swipe or tap) or cash found in a wallet/purse.
If you have non-backed-up 2FA tied to your phone, you should fix that. Batteries die, and phones can be physically damaged, bricked for some software reason (they're computers, after all), dropped into the ocean or off a cliff, or just legitimately lost (ie: falls out of pocket into the cracks of a car seat and battery dies).
I won't weigh into the punishment-deterrent argument at all, I'm merely pointing out that in theory there's actually a lot less disruption having your phone stolen vs having a wallet/purse stolen. Both suck, of course. Replacing a phone is almost certainly more expensive, but it should be significantly faster to recover from. And backup your 2FA.