C1 is high school level indeed and C2 is academics. this has been studied on native speakers:
me> I'm looking for studies which examine citizens language proficiency in their native tongue in the European language reference framework i.e. b2 C1 C2
also here is the "self assessment" on the CEFR home page:
Self-assessment grid - Table 2 (CEFR 3.3) : Common Reference levels - Common European Framework of Reference for Languages (CEFR) https://share.google/E6POb6UYC53cUkxXg
C1 is high school level indeed and C2 is academics. this has been studied on native speakers:
me> I'm looking for studies which examine citizens language proficiency in their native tongue in the European language reference framework i.e. b2 C1 C2
Gemini> https://share.google/aimode/bImgIsAl5VfAcuoFl
has links to studies
also here is the "self assessment" on the CEFR home page:
Self-assessment grid - Table 2 (CEFR 3.3) : Common Reference levels - Common European Framework of Reference for Languages (CEFR) https://share.google/E6POb6UYC53cUkxXg