As a German, I can say that Scholz is the worst chancellor we ever had. The main reason people want him to resign is that he is not leading. There is constant quarrelling within the three-party coalition that builds the current government and he does nothing to stop that.
Meanwhile our industry is shrinking, the education system is deteriorating and we have irregular and uncontrolled immigration.
Regarding aid for Ukraine, the German population is split in half, so this is - at least in my perspective - not the main cause of disapproval.