Every time I open a file, comments are visible and I have to hide them manually with Shift+C. There's no way to set this once and forget it. A simple toggle in account preferences — just like the light/dark theme switch — would be perfect. Set it once, and comments stay hidden by default across all files.
Also, visible comments noticeably slow things down, especially on older machines. Hiding them by default would make Figma feel much snappier day-to-day.