I've found out that the drums can be extracted extremely well from a mix. Following that, the bass tends to extract good enough for government work. Both of those are generally in a section of the spectrum without a lot of overlapping other instruments.
Vocals are OK in most cases as long as you're not looking for a pristine track.

I've tested most of the major players in the stem extraction game and some are better than others but none of them are at the point that I can take those extracted stems and use them in a professional mix. I end up in most cases, trying to hide the defects and deficiencies in the mix, which of course, results in a subpar mix.

I have no doubt that at some point in the future, AI will be able to "unbake the cake" as has been mentioned. We're not quite there yet.

You can find my music at:
www.herbhartley.com
Add nothing that adds nothing to the music.
You can make excuses or you can make progress but not both.

The magic you are looking for is in the work you are avoiding.