“Einstein merely reinterpreted Lorentz’s transformations.”
“Einstein had to get help from real mathematicians.”
“Einstein didn’t come up with anything new; only piecing together the theories of others.”
“Einstein made many mistakes while trying to advance his theories.”
Reinterpreted? Help? Pieced together? No fear of failure?
Those ARE the attributes of a genius. The ability to see the big picture, figure out a complicated puzzle, recognize the need for getting certain experts involved, and relentless pursuit of knowledge, are what makes a genius so prolific.
Those common criticisms of Einstein are evidence of his high intelligence.
If you study his many discoveries and make yourself aware of the limitations of the experiments and theories of his time then you can only come away impressed by his genius. He was one of the greats.
People who don’t understand this tend to make themselves look like fools when they belittle his genius.