Not just slightly more power. A lot more power.

Mind you, performance went through the roof compared to 2/3G. Performance per watt went up. But to get that sweet 200-600Mbps wireless, you need more power. More uptime on the modem.

A phone from 25 years ago would "stay connected" to the network but idle the modem or even shut down higher functionalities beyond the standard connection ping. A modern phone is CONSTANTLY streaming data. Push notifications. Optimised download of music, syncing of photos, emails, chat messages for your 74 different apps in their different protocols. There's no built in protocol to optimise a specific channel (SMS/MMS/RCS usage is considerably lower than iMessage, WhatsApp, Messenger, Viber, Telegram, etc.).

All that creep uses up resources. And unfortunately, the Windows Phone approach of designing for the lowest common denominator, with sane background task rules etc., went out the window around 2014 (even on desktop).

All of this combined makes a modern 3310 nigh impossible.

Or, you can have it, but it's not a phone worth having, because all it will be able to do is call, send text messages, and maybe have a basic browser built in...