Is it something like: QM and QFT are the same thing, and will always give the same answers, as long as you don’t ask QM the wrong questions?
More along the lines that QFT is a subset of QM and can not give different answers. If you think that QFT and QM don't say the same thing then you are in error because as the mathematics reduces to exactly the same thing.
QM was the historic generic version but as we understood fields in particular physics we were able to turn the QM into a more controlled subset of the field interactions.
In most of our physics the forces are known and so QM=QFT in those domains. We don't have gravity encapsulated in QM and it was found that as the energies was increased in colliders that forces seem to merge. Our highest point we have gone back to electroweak theory (
https://en.wikipedia.org/wiki/Electroweak_interaction).
You may want to review the known and expected field merges
So at this stage we are still in search of a Grand Unified Theory and higher up a theory of everything.
The question of whether QM requires and needs fields to operate is unanswered. All we can say is that it works in fields and even as those fields merge at higher energies. The question is hard to settle without the full theory of everything because the mathematics of QM works without the fields.
There are no known discrepancies between QM or QFT with any experiment ever done.
