I mean, if you want to stick to the 1.5 MB/s transfer rates of USB 1, more power to you.

Analog audio technology was basically perfected 40 years ago with the Walkman. You couldn't develop a significantly better connector today, even the size was optimal for small portable devices.

Data transfer technology OTOH is still improving by leaps and bounds, and the old ports are too big for modern portable devices like tablets and phones.

Agreed! Now XLR, THATS a good standard. Been around since the 1950s at least, and still the de facto connector today. Sure, you need to insulate against background interference and account for ground hum, but honestly that makes me for a clean connection when done right. XLR and Ethernet is all we need.

i still pine for the world envisioned by the first PoE working group; a world where every house's power outlets are just rj45s.

Wow! Never knew this was a thing. Would that be enough to power heavier load appliances (toaster ovens, window AC, etc)?

it's at that state now, yes. 100W PoE is standardized and available on the market. the standards body dragged their feet for a couple decades, vendors implemented their own proprietary high-power PoE injectors and devices, and a lot of the momentum behind PoE died out due to incompatibility hell. imagine every power outlet in your house was networked, could support gigabit data transfer, and the whole thing was so safe you could jam a fork into the outlet whenever the whim struck you -- that was the original dream.