It'll take either the next Einstein or some groundbreaking experimental observation to get there in my opinion.
If it was possible to incrementally fix these theories, the army of postdocs working on these would have already done so in the last decade or so.
Some once-in-a-generation scientist has an intuition that turns out to be true and mathematically elegant.
It gets proven experimentally years or decades later.
Relativity was exactly like this.
It shows both how Einstein very much didn't make the theory alone, was inspired to take impotat technical steps by work of other thats that created a theory based on his principles before him, and that actually he first created (in intense collaboration) a failed theory that got Mercury's anomaly all sorts of wrong.
That’s a bit simplistic. There was a lot of research activity around the aether in the late 19th century that was ultimately useful for the foundation of special relativity. Like the Michelson-Morley experiment, which was supposed to measure aether winds, but showed it did not actually seem to exist. Lorentz developed his transform as a theory of the aether, but it became a cornerstone of special relativity. Einstein based his ideas on a lot of things that were done a couple of decades before, some of which were supposed to be part of a theory of the aether.
There was actually quite a lot of activity and vigorous debate between aether and something else, unknown at the time, that turned out to be relativity. Einstein did not just show up and invent everything. There is a very quick overview of this here: https://en.wikipedia.org/wiki/History_of_special_relativity
If you revisit what I wrote, you'll find that I agree with you.
There was vigorous debate about a wrong and an unknown thing (both was basically wrong) and it took Einstein's intuition and the new GR math to turn it into science.
I was drawing a parallel between this and the current MOND, string theory, dark matter debate. More specifically, I'd even say dark anything is our generations aether!
My point is that you likely can not.