I'm frankly baffled at all these reports of IR being unreliable and slow. It... wasn't. Not for the file sizes of the day. I exchanged plenty of files back in the day, even at 115200bps a picture would be 2-3 seconds tops (pictures were small!). And when devices started supporting 4Mbps, even a large-ish MP3 would go in 5-6 seconds. All without setup or pairing, beautiful. Huge files (like full resolution pictures from an SLR camera) would take a while - but frankly they took almost the same time with a cable! You'd just have to plug their memory card directly into your computer if you were in a hurry.
The only really clunky use case for me was internet access - keeping phone and laptop positioned and aligned for 30 minutes was limiting.
And yes there IS plenty of bandwidth at those frequencies. In fact latest IR standards reach 1Gbps, but it's pretty much extinct. There was an attempt called Li-Fi to use it for as a wireless networking but I don't think it went far.
What I really miss is OBEX (Object Exchange), which worked also over Bluetooth, and which Apple sadly chose not to implement: simplest protocol to just ship a file or a contact vCard over, no setup, just worked - and it's been a standard for 20+ years. Early Android had it too, it was since dropped I think. Sigh.
You’re either misremembering things or talking about an era after Bluetooth had already taken off.
In the days before Bluetooth, transferring MP3s over IR took multiple minutes, even on high end (for the time) handsets.
And the fact that you needed to keep line of sight during the whole process meant your phone couldn’t be used that whole time. Which was a real pain in the arse if you got a text message or phone call while trying to transfer a file.
IR was really more designed for swapping contacts. In fact that’s exactly how BlackBerry (or was it Palm?) marketed IR on their device: a convenient way to swap contact details. But you’re talking about a few KB vs several MBs for an MP3.
The tech has definitely moved on since. But then so has Bluetooth, WiFi and GSM et al too.