If he's referring the flip phone, and not the Droid Razr, then we're talking about a phone that had a standby time measured in weeks. At best it lasts probably 10x longer than today's smartphones so even a 75% reduction in battery life is still better than what we deal with today.
Some people still want their phone to (1) make phone calls (2) make phone calls. For them a phone that makes phone calls and the battery lasts a week is far more full featured.
That's assuming they are still manufactured. With my old blackberry there were batteries on Amazon, but they were clearly expired stock and could barely hold a charge.
Some batteries seem to live on. I bought a no-name cheap dashcam for my car, and was surprised to see that its battery was identical to the one in my first Nokia phone.
A feature of the Razr that I desperately miss from modern phones: it would fire the alarms even when the phone was turned off. Somehow this ability has been lost on smartphones, and people behave as if it is a technical impossibility, but the Razrs managed it.
With the in-built BREW environment and the SIM "capabilities", it's probably a lot less "trusty" than an iPhone -- especially an iPhone with iCloud turned off.
The razr came out 7 years after the startac - there's no way they could have built the razr with 1996 technology. That's like saying the McLaren F1 is what the ford model T should have been...