When you have to choose between hidden variables, nonlocality, and many worlds, the opinions differ wildly which one of these is more simple.

Everyone claims their version is the most simple and logical, but then others disagree.

Surely there are people who see the equivalence of the interpretations, and don't paint themselves for color war?

Yes. I should not have said 'everyone'. Those who have one favorite interptetation.

If you are talking about Pilot Wave Theory - it definitely is not simpler mathematically. It might not require complex numbers, but it still requires the same number of parameters. It is actually more complicated to do multi-particle physics in this setup. But at the end they are just equivalent descriptions (same mathematical object, different ways to describe it).

Many-words is pleasant because it requires (arguably) less "mental gymnastics", but again, it is just an interpretation of what the equation means. It is still the same equation, the same mathematical object.

The claim is that Quantum Mechanics (or QFT more generally) is not a complete theory (and we do know that to be a fact, it does not work when space-time curvature is important). The only reason I personally find Many-words interesting is because it might be easier to generalize to a complete theory. But again, if we are constraining ourselves to flat space-time, all those interpretations are completely equivalent.

The problem isn't to get the right answer. When you have a recipe that works reliably for a known set of conditions, you're not doing science any more - you're doing technology.

The problem is to work out which questions to ask next. The different interpretations should eventually diverge into edge cases - of curvature, of observable other universe, or of some other difference - where they no longer predict identical results.

An incomplete theory suggests at least some further distinctions are possible. They may or may not be possible with current interpretations. They may need a completely fresh interpretation. But the distinctions matter, and it's important to consider the different directions they point in.

"...QFT...does not work when space-time curvature is important". Forgive the probable confusion of an ignoramus, but is there significant space-time curvature in the vicinity of a gold atom nucleus? I ask because I remember these claims about special relativity and the gold atom: https://www.fourmilab.ch/documents/golden_glow/ - of course, I could be dreadfully confusing special relativity effects with general relativity effects.

You are indeed confusing special relativity with general relativity.

Special relativity says that when things begin moving fast, they weigh more. Gold's properties are due in part to the fact that the electrons move so fast that relativistic effects alter the shape and energy of the orbitals that they stay in. That's special relativity.

In order to get significant curvature you would need the amount of gravity to be created to be significant. But electromagnetism is about 10^39 times as powerful as gravity. We only notice gravity on a macro scale because positive and negative charges almost perfectly balance. However on an atomic scale, the theoretical effects of Newtonian gravity are many orders of magnitude smaller than any possible measurement error. Let alone the size of general relativistic corrections to that theory!

You can use the Schrödinger equation in a classical, non-relativistic, space-time, do calculations and get a lot of the chemistry explained more or less correctly. There is no speed of light, and electric fields have immediate effects over long distances.

But to explain the electron transitions that make gold yellow, you need to use the Schrödinger equation in a relativistic space-time. (But just special relativity suffices here, no need to go to general relativity.)