I think there is also the issue of the gender and age composition of the refugees. The current waves of refugees are mostly women with children. Men who are Ukrainian citizens are not allowed to leave. So the vast majority of the Ukrainian refugees are women and children. Societies usually have a greater sympathy when it's women and children fleeing.

For example case of Syrian-Ukrainian boy:

https://medium.com/@modernrenaissanceman/the-powerful-story-of-the-11-year-old-syrian-ukrainian-boy-who-travelled-1200-km-to-safety-alone-9bd0e487a1fd