While watching YouTube, I came across the following popular video:

Why no one has measured the speed of light

It appears to say that speed of light could depend on direction it is traveling and we would never know.

I was under the impression that the Michelson-Morley experiment was intended to verify that very assumption. If velocity of light were different in different directions, we would see a pattern. If memory serves me right, the experiment was repeated several times in various locations. None of the observations were inconsistent with constancy of the speed of light in all directions. Where is my logic wrong?