>Keyboard and mouse move on from PS/2 to USB
>Microphone moves on from 3.5mm jack to USB
>Speaker and headphone still use 3.5mm jack to this day
Why is that?

just stop with the retarded frogposting already
>>>/g/sqt

>>106134348 (OP)
Most motherboards still come with a microphone jack on the integrated audio. We stopped using PS/2 because it wasn't plug and play, and unplugging a keyboard could make your computer a-splode!

>>106134373
Officially, no, it wasn’t plug and play.
On my PCs at the time, though, you’d need to test the plug and play-ness less than once a year.
And I never had any kind of crash back to the original PC and PCjr when doing so.
So, in practice, it just worked.
A lot of keyboards of the era were built like brick shithouses, and the PCjr had infrared, too.
Still never needed USB.
It’s a shame IR never caught on more though.