Ngl, SailfishOS could have been the third major mobile os but thanks to saturation it couldn't hold it's position. It's such a beautiful operating system that I spent 6 months trying to port it to my device (I failed) but eventually realized that it's not that supported and kind of closed source and dev rarely works on the source. It has it's own advantages and disadvantages but compared to android, it could have been a real deal to iOS

Truth