It depends which Nationalities they have.
If they are Israelis and they did go out until today, they did not believe it will happen. Now they stuck at the border. Its very very hard now to leave and it was quick dumb not to go…… But on the end we are always smarter.
If they only have Ukrainian passport they most likely had no option to leave. Many Jews in Ukraine are very poor as well as many in the country: Money, Shelter and logistics are the problems.
For example, my mother today was on the way to her work when I called her to let her know about the Russian occupation. She thought its only in east. I told her that they attack the whole country. She did not believe it.
This happened to many other Ukrainians. Many surprised on the way to work.