Some theoretical stuffs have being tested and accepted, while others (theoretical) remained untested.
There are some stuffs in Relativity and in Quantum Mechanics that remained theoretical and untested.
But you need to remember, sciences are not just accepted experimental knowledge...they (sciences) also can be long (and ongoing) waiting game.
Take for instances, the geocentric model vs heliocentric model about Earth-Sun relation.
Geocentric model, although it haven’t been mathematically understood until Claudius Ptolemy, a 2nd century CE astronomer, it have been generally observed and accepted the Earth was fixed while the sun move across the sky, from east to west, since Neolithic times and in Bronze Age of Egyptian astronomy and Babylonian astronomy.
Heliocentric model, is where the Earth and other planets orbit around the stationary sun, have been mathematically formulated by 3rd BCE Greek astronomer Aristarchus of Samos, but not tested through observations.
Despite cropping up from time to time, by other astronomers after Aristarchus in centuries to come, from other Greek astronomers and Hindu astronomers, and even a Muslim astronomer (but who would later retracted) would visualized concept of heliocentric, heliocentric model was highly popular.
So geocentric model on planetary motion, was the accepted concept for millennia. The geocentric model was accepted as science since Ptolemy wrote his astronomy treatise.
Then heliocentric concept was revived once again, during the Renaissance, by Nicolaus Copernicus, again mathematically, but in the early 17th century, the newly developed telescope was invented (by names that I don’t recall) and heliocentric was discovered by Galileo.
But as I said earlier, sciences can be long and ongoing waiting game, not just pioneering or discovering stage, but scientific concepts and theories may take also take a while to be refined and modified/updated.
While Copernicus was correct about the heliocentric concept, he was wrong about the planetary orbits being circular. Johannes Kepler corrected that, proposing that the orbits were elliptical in shapes. Further refinements to heliocentric model was introduced by Isaac Newton, who proposed gravity and gravitational forces were responsible for the planets’ motion around the sun.
So what started by Hellenistic astronomer Aristarchus of Samos, it took over 1500 years to vindicate Aristarchus’ mathematical/geometric concept.
The point looking back at history of geocentric vs heliocentric concepts, that heliocentric was never science, until it was finally discovered and tested by Galileo.
Likewise, it took centuries that started with Newton on gravity, that was later refined by Einstein, with General Relativity in 1915. And it may be further refined in the future with Quantum Field Theory (eg Quantum Gravity), which have chance unifying two opposing theories - General Relativity and Quantum Mechanics.
Ever since Einstein, theoretical physicists have for decades been trying to unify these 2 concepts, including String Theory and Superstring Theory, but these two concepts have become increasingly complex, that they have become unworkable and unwieldy. Einstein himself tried to unify 2 theories, but couldn’t do it.
Quantum Field Theory (QFT) seemed to be the likely candidate to succeed what Einstein started and where String and Superstring theories have failed. But you will never know, because there may even be better alternative than QFT.
Like I said, sciences may (or may not) catch up the theoretical parts, and as I said, it may take times.
And it may take times, for concepts to be refined, modified and updated.
When I look back at, history of gravity, I think Galileo testing falling objects from Tower of Pisa, predated Newton proposing formulating the universal gravitation. But Galileo couldn’t and didn’t describe the forces responsible for things falling.
And while Newton described gravity and its forces as being caused by “gravitational fields”, today “gravitational field” have been dropped, since Einstein described gravitation as being property (or curvature) of space and time.