The study by the German Centre for Integration and Migration Research (DeZIM) found that 21% of respondents reported thinking about emigration. Among Germans without a migration background, the share was 17%. Those who themselves immigrated to Germany were twice as likely to consider leaving (34%).
I think Germans who complain a lot about Germany lately do this either out of habit at this point or they really have no idea about the economic situation on a global scale. Things aren‘t going much better anywhere else. At least not for people like me and you.