> So if there are 3 competitors and one drops out, the other two are now guilty of something?
Well, Microsoft eventually got all but forced to port Office and, for a time, Internet Explorer to macOS to evade getting sanctioned by the EU.
In a similar vein, if the market is not healthy any more, the duopolists may be forced by regulatory authorities to make life easier for potential startup competitors: open up file format specifications, port popular applications with network effects (iMessage, Facetime, Find My in the case of Apple) to other platforms or open up specifications to allow others access/federation.
> Well, Microsoft eventually got all but forced to port Office and, for a time, Internet Explorer to macOS to evade getting sanctioned by the EU.
I have seen some people assert this a few times in the last couple of weeks and I don’t know where this comes from. This is not at all what happened.
This was part of an agreement between Apple and Microsoft in 1997, long before any EU decision. Microsoft bought some Apple shares and agreed to support office on MacOS for a few years, and Apple made IE their default browser.
One can argue whether they did it to improve the optics in their (American) antitrust lawsuit (and there are several details that do not make sense if it were the case), but it certainly was not forced on them by any court.
Well, Microsoft eventually got all but forced to port Office and, for a time, Internet Explorer to macOS to evade getting sanctioned by the EU.
In a similar vein, if the market is not healthy any more, the duopolists may be forced by regulatory authorities to make life easier for potential startup competitors: open up file format specifications, port popular applications with network effects (iMessage, Facetime, Find My in the case of Apple) to other platforms or open up specifications to allow others access/federation.