I've come to think that whatever eventually replaces USB should add some separation between power and data. Let's call it MSB (Multiversal Serial Bus). Maybe something like this.

MSB would define 2 connectors: a data connector and a power connector.

MSB would also specify that if you have both data and power connectors they should be physically laid out in data/power pairs and would define the spacing/positioning (e.g., the power connector should be parallel to the data connector 2 mm apart with the power connector above the data connector).

The idea behind the layout specification is that for applications that need both the power and data connectors you could make cables that include both, with the housing at the ends holding the two connectors fixed so they can treated as a unit when it comes to plugging into things.

The power port would include data line, but they are just used for power negotiation.

The data port would include power, but just a fixed voltage and max current, comparable to pre-high power USB, so for low power peripherals you would just need to use a data port. I.e., for low power peripherals it is pretty much just like USB.