As the title implies, I can not use snap as the fuse filesystem ist not fully supported.
I don't know what the fuse filesystem is and why it seems that I'm the only one with this problem on a newly installed Ubuntu 18.04.4 LTS (GNU/Linux 4.15.0 x86_64) machine.
And it seems that snap is not shipped with my version as other sources are saying ("This packaging system, available on Ubuntu 18.04 by default..." sauce)
The full error message:
system does not fully support snapd: The "fuse" filesystem is required on this system but not available. Please try to install the fuse package.