the analogy is baloney. floppy drives didn't get removed from hardware just because they were "old" or "made the computer fat," ... floppy drives were removed from computers because their entire raison d'etre was becoming more rare - the Floppy Disk. It was actively being replaced by CDs because it wasn't sufficient as a storage medium any more.

So for the analogy to make sense, 3.5mm plugs would have to be dying, actively and ubiquitously being replaced by ... whatever. Lightning? USB-C? But they're not. The 3.5mm jack and headphones in particular are probably more common now than ever before.

I personally would love to see the headphone jack become more useful in lots of different ways. Square managed to make a CC reader that plugged into the 3.5mm jack. Impressive, using it as a data port for simple data. Can we do more of that? What if a 3.5mm cable was a way for your phone to connect to various IoT devices to pass the basic setup data like your wifi SSID and password instead of this goofy process of broadcasting it's own wifi network that you have to connect to. Any app can push signals out the headphone port, and it works the same across iOS and Android. Maybe I'm an idiot and that'd never work but the point is: 3.5mm isn't dead. It's very much alive and kicking.