Even Samsung have practically given up on Tizen. In smartwatches, the plug has been pulled, and for smart TVs, it's not updated anymore, because they probably realized that it's a waste of effort
Is that even a battle worth fighting at this point?
I think they all know the safest option is to leverage Android’s ecosystem and add your own extras to it. Starting from scratch is like 90% chance of wasting lots of money and have no profit at all.
That’s why these massive projects aren’t usually started by companies, but by passionate individuals or orgs. They require a different incentive than the next quarter earnings.
Starting from scratch is a worthwhile investment, if you can carry it to completion. Samsung never do this, so it was a waste of time from the start. Admittedly, their Tizen watches were leaps ahead in performance, compared to the Android alternatives, but they completely gave up on attempting to improve any of them