I agree it would be convenient. But consider the new dangers: 1) pickpocketing would suddenly be 3x as profitable and 3x as easy, 2) lose one thing and you've lost everything, 3) if one thing stops working, everything stops working, 4) venues where you have to give up your phone means carrying extra cash in.... a wallet, 5) cybercriminals can now steal much more from you without ever getting near you, 6) I imagine there will never be a universal standard for these things so changing vendor will be quite difficult.

I can theoretically leave my home with just my smartphone. I can use it to pay fare at the local train station, get directions to restaurants, read the news, pay for food and coffee, and even lock / unlock my apartment.

I do still bring my wallet and keys, because I'd hate to run into a scenario where my phone does get lost, stolen, or damaged, leaving me stranded without a way to get home. But the concept is definitely there, and for someone less paranoid than I, it's definitely possible to live a life of convenience.

You can still use phone to do everything for convenience, but carry stuff as a backup.

1) so lose the keychain and evenly distributed your keys in all your pockets to minimize the percentage of personal items lost per successful pickpocket

Agreed completely, but keys/IDs work 100% of the time. Even if virtual versions work 99% of the time, that's still not enough.

That day is closer than you may think. I sometimes only have my phone with me as i can pay using only it (something like Google/Apple pay, but through my bank's app) and can unlock my front door thanks to Home Assistant. Both of those (should, I don't have one) work with a smart watch.

I’ve been able to do this for about five years over here in the U.K. - and very regularly do.

Can’t help you with the keys or ID (yet), but I exclusively use the stored cards on my Apple Watch for payment. It is so reliable (in Norway) that I haven’t brought my wallet on normal days in 2+ years.

Even on vacation in Northern Europe (Belgium, Netherlands, France, Germany) and on a business trip to the US (California+Texas) this year, I very rarely had to use the physical cards. NFC just works. Everywhere.

I still bring the cards on important occasions or when going further than a normal drive, though - a testament to the fact that the day you’re longing for is not _quite_ here yet.

NFC adoption has been improving in the US but still far too many big retailers that still won’t accept it, even when they have the equipment.

Or they accept it in theory, but it's not working for some reason. It's so silly.

I’ve long wanted to do this, as a kid I added NFC (at the time, simply RFID) door locking to my 1989 jetta so I didn’t have to fumble for keys. It turns out I do live in the future. I don’t lock my house, so that’s one less key right away, but there are some keyless door locks on the market if you still need them, and those could probably be automated with something like home assistant. I have a tesla that uses a phone for a key. Work has a key card, it’s a proprietary system but I could shrink one into a ring or something. I don’t carry cash, but instead use a magnetic wallet on my phone from popsockets (apple makes one too) for physical cards, although I mostly use apple pay. No digital driver’s license here yet however, so I needed a place to keep cards anyway. In Seoul the metro pass is a simple NFC sticker that you place on the back of your phone. So, no keys for me! Everything is built around the phone, which is fine until I lose access to it…

My personal example of this, allowing me to cut down on my daily carry:

- Cards stored in Apple Wallet

- Health/Vehicle insurance card available via an app

- Driver's License available via state-issued app

- FlexNT NFC implants located in both of my middle fingers, allowing me to lock/unlock my house using Home Assistant + a scanner I built based on an ESP32 & PN532.

Sure, I'm more reliant on the device in my pocket - which can definitely be an issue if it's dead. However, I work from home and am rarely in situations where that predicament would arise.

It’s a great idea until the battery in your devices fail and you’re stranded somewhere with no ID, no way to communicate, and no money for a train ticket.

Is that any different from losing your wallet in the pre-smartphone era though?

Depends.

In pre-smartphone era I usually had an 'in case of emergency' bill tucked away in my ID, which was in other pocket than wallet.

wouldn't the proper comparison be to losing your phone in the current era but still having keys and wallet?

I could leave my keys at home, but most days now I'm traveling with my security keys, partly to keep them away from my desk at home and partly in case I might need to login to a secure account while out and about.