"Insufficient space" error message

I am trying to donwload MacOS Ventura or Sonoma (idk which one yet) and this "insufficient space" message pops up even though I have plenty of space on my mac. Caches files are empty.

I litteraly moved 20gb of videos that were on my mac to a USB key and the exact same message shows up, with the same numbers (19,6 of 24.4 GB needed).

What should I do? This is a 2017 Macbook Air if y'all are wondering.