I get what you're saying but that's the connector at one end - you still have a mains plug or USB socket at the other - so you could easily have an adapter. The point would be that everything would communicate with everything else. No differing protocols and incompatible equipment - although you might need the odd adapter here and there.
And on computers, while you may have different shaped ports - you do have standards like USB, serial, parallel, SCSI, ATA or whatever. Most of these are backwardly compatible with earlier versions.
Of course, one day you may have the problem where you have to move on and start new. If you planned well enough, you could ensure that when the Mk1's go, the Mk2's will work with Mk3's. When the Mk4's go, they will work with the Mk3's but not the Mk2's now being phased out - and so on. Obviously this means much tighter planning.
We're allowed to go a little bit crazy here aren't we? I mean, it's not going to happen!