Why stop at computers? Dewalt, Milwaukee, Makita, and every other power tool uses its own proprietary battery connector.
Why stop at DC power? Last I checked, Germany, France, England, Italy, and many of the smaller countries all had their own AC power connectors.
Why stop at hardware? iMessage, Hangouts, Messenger, Slack, and all the rest use their own proprietary interfaces. I still can't even save "a spreadsheet" in one program and reliably open it in another.
I can put any bit in any drill, and any blade in any saw, but as soon as electricity gets involved, everything gets stupid. A lot of programmers say they're interested in "visualization", but visualization was the default state of the world before electrons got involved. Most programmers use the invisible nature of software to disguise the proprietary and incompatible interfaces they're creating.
I hear a lot of developers complain about how their Mac laptop is no longer expandable or upgradeable, and then they turn around and use it to write a web app which uses a custom client-server interface with no public API or import/export. An industry is only anti-consumer when I'm the consumer.