So why do we have these threads right here, that prompted me to write this?
> Whether emergence can explain everything
Nothing can explain "everything". What does that even mean? I refer back to my comment. You use the right tool for the job, and that is a different one depending on context and "zoom level". See my comment? As I already wrote, even if you had a "perfect" low(est) level model, of what use is it to you on a much higher level? You cannot deal with an unmanageable amount of "low level" model (the "but in theory" argument is not even a good one in theory - reminds me of "but I can in theory imagine things happening at the exact same time light years away" before relativity became way too established for anyone to dare make that kind of statement to not be laughed at). You can't use the same model for everything. Even if you had the perfect knowledge of the lowest level you'd have "emergent models" on higher levels. You can't work with quantum theory to explain chess (which, in addition, is disconnected from the actual physical chess pieces used, it could even just be electrons in a computer instead of wooden or metal or plastic chess pieces).
PS:
Using the opportunity of the follow up comment to add to my original one:
Another POV is - just another mental model, not "the ultimate explanation for everything", one model among many - is that the low(est) level just is the hardware, the silicon. When you write software you don't care about the (exchangeable, extremely variable) hardware underneath. Without it there would not be "chess" - there would be many "chesses" because the game in software would be something completely different from the game using wooden pieces. We would not see any of those high level concepts because we would drown in detail.