Einstein's speech in the Nobel ceremony was entirely about relativity, which had been accepted as fact since 1908 within the physics community. General relativity was immediately accepted as fact on being published. The same is true for the discovery of gravitational waves.

Relativity was excluded from the prize for relatively obscure reasons, the then famous philosopher Henry Bergson objected to Einstein's concept of time at the time that the committee met to decide on the prize[1]. To top it off Alfred Nobel was not a fan of theoretical physics and made it clear that only experimentally verified theoretical results should be awarded[3]. This is at odds with the physics community. No prominent physicist has objected to relativity since 1910.

If you have actually studied physics, you will see that special relativity is "obviously" correct. There is no reasonable explanation of electromagnetism that doesn't logically imply special relativity. If you accept Maxwell's electromagnetic field equations, special relativity follows mathematically from it.

Theoretical Physics proceeds by exposing contradictions within theories and solving them.

1. Galileo challenged Aristotle's physics by assaulting the contradictory laws for heavenly and earthly bodies

2. Newton gave it a sound mathematical footing resolving contradictions between the laws of heavenly and earthly bodies

3. Maxwell resolved contradictions in Biot Savarts law by introducing displacement current and thus predicting that light is an EM wave

4. Special relativity eliminated the extra ordinary coincidence that prevented any physical experiment from distinguishing an electric field from a magnetic field, even in a theoretical setting, by proposing that the speed of light is constant wrt the observer [2]

5. General relativity solved the extra ordinary coincidence that we cannot distinguish gravity from acceleration while also resolving contradictions between gravity and special relativity.

These theoretical explanations were adequate by itself and did not need experimental verification to be celebrated. Because they solved long standing contradictions and coincidences in a simple compact explanation that reduced the axiom set in physics, not increase them.

That's what differentiates theoretical physics from experimental physics. Alfred Nobel had an aversion to theoretical physics, that's why Higgs had to wait for his prize for decades. But the physics community always knew that the Higgs boson existed. Otherwise, they wouldn't spend billion plus dollars on speculation.

Stanford would not hire Susskind as a professor in theoretical physics if the physics community thought his works are flights of fancy. The same goes for the Lucasian chair conferred on Stephen Hawking, who worked almost entirely in theory with very little experimental verification for his work. Einstein was offered professorships in theoretical physics at various institutions in the 1910s, including the prestigious ETH Zurich well before any sort of experimental verification of his theories.

[1] https://nautil.us/this-philosopher-helped-ensure-there-was-n...

[2] https://www.fourmilab.ch/etexts/einstein/specrel/www/

[3] https://academia.stackexchange.com/questions/63049/can-a-the...