if libreoffice is unusably tiny on your high-resolution display (on Linux), install libreoffice-qt6 and do this:

$ SAL_USE_VCLPLUGIN=qt6 libreoffice --calc

you can also use e.g. SAL_FORCEDPI=100 to override the automatically detected scaling factor

as a bonus, it also enables a (quite well working) dark theme

(there is a gtk3/gtk4 variant of this command as well but i haven't tested it)