The concept of luminiferous aether was discarded- not because of the discovery of Theory of Relativity, but becauae of the Michelson and Morley Experiment [0].
It is often joked about in High School and college Freshman Physics circles- Michelson received Nobel Prize in Physics [1] for a literally failed experiment.
[0]: https://en.wikipedia.org/wiki/Michelson–Morley_experiment
[1]: https://www.nobelprize.org/prizes/physics/1907/summary/