Nice finding. Now I see that
$ sudo apt autopurge snapd
Reading package lists... Done
Building dependency tree... Done
Reading state information... Done
The following packages will be REMOVED:
snapd* squashfs-tools*
0 upgraded, 0 newly installed, 2 to remove and 54 not upgraded.
After this operation, 94,3 MB disk space will be freed.
Do you want to continue? [Y/n] n
is safe, but
$ sudo apt autopurge gir1.2-snapd-1:amd64 libsnapd-glib1:amd64 snapd
Reading package lists... Done
Building dependency tree... Done
Reading state information... Done
The following packages will be REMOVED:
apturl* apturl-common* ayatana-indicator-sound* bluez-cups* cups*
cups-browsed* cups-core-drivers* cups-daemon* cups-server-common*
gir1.2-goa-1.0* gir1.2-snapd-1* hplip* hplip-data* libcanberra-pulse*
libcupsimage2* libgutenprint-common* libgutenprint9* libhpmud0*
libimagequant0* libpulsedsp* libsane-hpaio* libsbc1* libsnapd-glib1*
libspeexdsp1* printer-driver-gutenprint* printer-driver-hpcups*
printer-driver-postscript-hp* printer-driver-splix* pulseaudio*
pulseaudio-module-bluetooth* pulseaudio-utils* python3-dateutil*
python3-debconf* python3-olefile* python3-pil* python3-renderpm*
python3-reportlab* python3-reportlab-accel* python3-software-properties*
rtkit* snapd* software-properties-common* software-properties-gtk*
squashfs-tools* ssl-cert* ubuntu-mate-core* ubuntu-mate-desktop*
ubuntu-release-upgrader-gtk* update-manager* update-notifier*
update-notifier-common*
0 upgraded, 0 newly installed, 51 to remove and 54 not upgraded.
After this operation, 144 MB disk space will be freed.
Do you want to continue? [Y/n] n
is not.
This is upstream (Ubuntu) decision targeted on user comfort.
For example CUPS provides drivers for printers which are released very fast (faster than LTS release cycle of course). So having CUPS as a Snap is a good idea, if we or Canonical care about the users. PPA maybe better, but they chose Snap...