Einstein claimed he hadn’t heard of the MME results prior to formulating his theory, despite the fact that his mentor, Hendrick Lorentz, knew full well about it, and had come up with his Lorentz Contraction and dilation formulas in an effort to explain the puzzling MME results.
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IIRC, Einstein did say he knew of the Fizeau experiments and stellar aberration, which was all he needed to come up with his idea that there was no ether.
What really set Einstein apart was that he believed particles were real, a forbidden belief in German physics at the time. In fact all three of his great 1905 papers were centered on the idea of particles being real, and extensions of his graduate work. It helped that Einstein had little to lose. He was young and not even a professional physicist.
Most of the work for Special Relativity had already been done. That’s why it’s called a Lorentz Contraction rather than an Einstein Contraction.
Like so many successful people, Einstein was in the right place at the right time with the right idea.
Ether there is, or ether there isn’t.
I have also found this of interest:
In 1920, lecturing at the University of Leiden, on the topic ‘Ether and the Theory of Relativity’, Einstein stated outright that the ether did exist, that is was necessary as a medium of transfer because light also had wave-like properties. He even wrote Lorentz to clarify this point.