If neither of the two major players can make an open, secure, _simple_, easy-to-understand, bloat-free OS, then we somehow need another player.
Presently (and I confess, my bias to seek non-state solutions may show here), it seems that a non-trivial part of the duopoly stems from regulatory capture insofar as the duopoly isn't merely software, but extends all the way to TSMC and Qualcomm, whose operations seem to be completely subject to state dictates, both economic/regulatory and of the darker surveillance/statecraft variety (and of those, presumably some are classified).
I'm reminded of the server market 20ish years ago, where, although there were more than two players, the array of simple, flexible linux distros that are dominant today were somewhere between poorly documented and unavailable. I remember my university still running windows servers in ~2008 or so.
What do we need to do to achieve the same evolution that the last 2-3 decades of server OS's have seen? Is there presently a mobile linux OS that's worth jumping on? Is there simple hardware to go with it?
I really hoped that Huawei would go for a fork of AOSP (they could even pull the changes from Google :-) ), but they chose to go with their proprietary HarmonyOS.