I'm not so sure about that. Perhaps during the hobbyist era of PCs, this was the case. But, I distinctly remember a world during the "dominance" of the PC that forced me to work with proprietary software just to be able to type out a document. There was really only one choice of computer to buy and one kind of OS to run on it. It was really hard to use a different OS on your computer, and it was risky too, since PC manufacturers would often not honor warranties if non-proprietary OS/software was used on the computer.
Even in those days we had more power than we do today. You had to use proprietary software but that software still worked for you and did your bidding. The computer ran the software you told it to run without complaint and it didn't matter that some "rights holders" were losing money or whatever.
At some point all of this changed... Software now works for the corporations and only allow us to do what they designed for us. If they don't like something, you just won't be able to do it anymore. You can't even program the computers anymore, that's now a privilege increasingly reserved only for "approved", "licensed" individuals.
Typing out a document? I wouldn't be surprised if the office suites of the future started automatically checking your work against some "rights holders" corpus that you're not supposed to copy and then preventing saving or printing until you fix it.
PCs have unique advantages, they enable things like Napster, Torrents, in-premise storage, and all kinds of autonomous servers that could never work with mobile computers and the cloud.
