QM is also demonstrated to scale beyond the "micro" realm:
https://spectrum.ieee.org/a-quantum-drum-brings-quantum-mechanics-to-the-macroscale
https://archive.fo/VSLWc
I didn't check the links, but generally your sentiment is true, QM effects can be see on large scale, GR effects can be seen on small scale. But my point is their "roots" are different
Oversimplified: GR was developed by observing macroscopic phenomena (gravity mainly), QM was developed observing microscopic phenomena (elementary particles mainly).
That is, at least the "mainly" parts I wrote there are "oversimplifications at best". GR was maybe mainly developed by thought experiments with regards to light speed.
Truth, yes.
QM is an enigma:
1. QM looks like something a menstruating witch on shrooms dreamt up.
2. So randomly often QM seems to correlate things we never imagined correlated.
