Wwyd with this apple tree

I moved in under a year ago and this massive apple was overgrown with blackberries. It took some time to even get in to realize that it had fallen over some time in the past. I'd guess 6+ years ago based on some of the branches growing straight up from limbs that were previously not parallel to the ground.  (And what I know about previous residents.)

It blossomed in patches this spring and only set fruit on one side. The apples are absolutely amazing. (Paradise if my plant ID app is to be believed.) Huge, fragrant, sweet. The tree is decades old.

While I hate the idea of getting rid of such a conceptually wonderful tree, it IS in a prime gardening location. If it's going to be a lost cause, I'd rather clear it off soon.
My inclination is to, at the very least, cut away the side that isn't producing fruit and see how the rest goes next year.

I'd love a miracle that would keep it producing though!  

"My inclination is to, at the very least, cut away the side that isn't producing fruit and see how the rest goes next year."

This would be my inclination, as well - if I didn't just leave it be. Over the time that is been downed, I'm sure there has developed an amazing symbiotic ecosystem within its branches, and in its specific shade. There is something to be said for lovely fruit within easy reach, shelter from the dangers above, for small critters, and support for other lovely fruits in easy reach. Maybe on the shady side, I'd add some perennial culinary &/or medicinal shade loving, flowing herbs, and on the sunny side, some sun loving ones, and possibly put a beehive nearby, as well. But... I think your photos show it as a thing of beauty and productivity, so...