Screenshot of a preprint on PsyArXiv (https://osf.io/preprints/psyarxiv/zue74_v2)
Screenshot of a file opened on OSF (https://osf.io/svrb3/files/38tkn)
The new design wastes so much UI real estate. For the preprints, the PDF only takes 30% of the width (with padding, 36%) while the sidebar and the metadata take 20 and 36% with no possibility of adjusting/hiding.
The OSF repos have a similar issue (though the old design had the bad proportions too).