Ubuntu <21.04 will set, by default, user's home mode to 0755 (effectively allowing all users to read some private files).
https://discourse.ubuntu.com/t/private-home-directories-for-ubuntu-21-04-onwards/19533
A more secure approach to file sharing should probably live outside of personal folders, e.g. shared directories.
There're still valid use cases where some systems like libvirt need access to user's home files in order to work, this can sill be supported via setfacl -m u:libvirt-qemu:rx ${HOME}.
Opening this issue just in case it goes unnoticed. Is not this library issue but a general Ubuntu "problem" which can be patched, if wanted, with a few lines like elgalu@1375bc5