When you ask academics questions like this it is a game to them and one of the rules is that you don't give the obvious answer, you show off by justifying less well known or expected people. The problem in comparing scientists from vastly different periods of history is that the nature of their work is so different and so you can justify almost any scientist who was at the top during their own era.
The fact is that most famous scientists were just men of their time and if they hadn't done their work and made discoveries, someone else would have done it in the same era. But Einstein's work on General Relativity was decades ahead of its time and his six papers in 1905 were and still are an unmatched achievement. The only comparable achievement was Newton's early work.
But something not usually realised by the public is that Einstein effectively wasted his later years by taking a fruitless stance against quantum mechanics which was the equivalent someone like Neil Degrasse Tyson becoming a flat Earther. So for this reason and also playing the game, an academic might want to dismiss Einstein. But they are wrong.
A measure of great / significant work is that the whole field looks different afterwards. And by that measure the work of Newton and Einstein did radically transform the field. Bohr did some great stuff but really he was one of many scientists chasing the tail of quantum mechanics, a field which was largely kicked into existence by Einstein's explanation of the photoelectric effect, with its quantising of light into discrete photons. This was based on Plank's earlier black body radiation work, the difference being that Plank considered it an inexplicable mathematical trick that made the calculations match the data, whereas Einstein decided to believe the face value of the mathematics and run with it.
It reminds me of a story where a critic said that if you ask modern violinists to list the best violinists, Yehudi Menuhin doesn't even make the top 50. But if you ask them to perform Elgar's violin concerto they all go straight to his recording of it.