The S23 has Wi-Fi 6E support, Bluetooth 5.3 support, twice as much base storage and RAM, 5G support, an in display ultrasonic fingerprint sensor, 3 high resolution cameras, 120hz refresh rate, twice as fast internal storage, a 33% larger battery, a much newer version of Android and to top it off a processor that’s roughly 3X as powerful as the S9.
So to me it might not be fair to call the S9 dialup but I would say a comparison between broadband and fiber is pretty accurate. At the very least the other features are worth upgrading for if not the speed. Now I suppose the S9 is still a perfectly good phone to be used as just a phone but these things are really portable computers and the increase in processing power becomes tremendous in a short period of time.