"In February 1933 while on a visit to the United States, Einstein decided not to return to Germany due to the rise to power of the Nazis" https://en.wikipedia.org/wiki/Albert_Einstein
Many ordinary Jews wanted to leave including my great grandparents and their relatives. The US put up a quota to keep most of them out and none of their visas were ever granted. Other than my great uncle who went to the US in early 1930 and my grandmother who survived a camp (my mom stayed hidden for two years). The remainder all died in camps. My mother told me my great grandfather continued to believe he was as good a german citizen as anyone right until they took him away in 1943.
Well known Jews could get out at least until the war.
I think the correct assertion would have been that more Jews would have left. Even the information you linked to suggests that, at least as of 1938, many Jews weren't convinced they had to leave yet.
Emmigration is difficult, especially if you're in the middle class.
What would need to happen for you to abandon your job/business, home, extended family and friends and home to move to another country? I don't know what the answer is, but I think in a similar circumstance my first instinct would be to hunker down and wait for things to blow over.
If you're poor and striving, I think these decisions are a bit easier. My grandparents all immigrated to the US from Ireland between 1929-1946. For them, the complete lack of opportunity made it the only decision that made sense.
Spooky23 is probably also right - it seems easier to move if you're at the top (internationally known and/or could walk into a good new job) or at the bottom (nothing much to lose), but harder at the middle class.
Many did.
"The United States was another destination for German Jews seeking to leave the country (in the 1930s)" https://en.wikipedia.org/wiki/History_of_the_Jews_in_Germany
"In February 1933 while on a visit to the United States, Einstein decided not to return to Germany due to the rise to power of the Nazis" https://en.wikipedia.org/wiki/Albert_Einstein
"(in 1938) Interrogation of Anna Freud by the Gestapo finally convinced Freud it was time to leave Austria." https://en.wikipedia.org/wiki/Sigmund_Freud