Docker-ce suddenly broke - cannot reinstall, hangs in systemd service enable

I know my question may be too generic but please bear with me for a moment:

I use ubuntu 18.04 LTS, and had docker-ce installed (using the official install procedure described in https://docs.docker.com/engine/install/ubuntu/) on a modern thinkpad. Nothing fancy about my setup.

A day or two ago, my system hanged when trying to poweroff my machine. Then, when I tried to use docker, the daemon was unresponsive, just hanged. systemd unit was loaded, but had not started. I assumed at that point that the poweroff hang was due to this docker daemon issue.

So I tried to purge and reinstall docker from the system. sudo apt-get purge docker-ce docker-ce-cli containerd.io Even this command hanged.

So I tried to manually unlock dpkg by:

sudo systemctl disable docker
pgrep -a apt
sudo kill -9 <apt process>
sudo rm /var/lib/apt/lists/lock
sudo rm /var/cache/apt/archives/lock
sudo rm /var/lib/dpkg/lock

also deleted all docker and containerd related files + disabled and removed systemd unit:

sudo systemctl disable docker
sudo rm -rf /etc/docker
sudo rm -rf /run/containerd/containerd.sock
sudo rm -rf /usr/bin/dockerd
sudo rm -rf /lib/systemd/system/docker.service
sudo rm -rf /var/lib/docker-engine
sudo rm -rf /var/lib/docker
sudo rm -rf /var/run/docker/
sudo rm -rf /var/run/docker.pid
sudo rm -rf /var/run/docker.sock
sudo rm /etc/apt/sources.list.d/docker.list
sudo rm -rf /var/lib/containerd
sudo rm -rf /opt/containerd
sudo systemctl daemon-reload

and restarted which then allowed me to finally run the purge command successfully: sudo apt-get purge docker-ce docker-ce-cli containerd.io

Then when I try to reinstall docker (using again the official docs method, stable channel), it hangs at enabling the systemd service:

...
Preparing to unpack .../5-docker-ce_5%3a19.03.8~3-0~ubuntu-bionic_amd64.deb ...
Unpacking docker-ce (5:19.03.8~3-0~ubuntu-bionic) ...
Setting up aufs-tools (1:4.9+20170918-1ubuntu1) ...
Setting up containerd.io (1.2.13-1) ...
Created symlink /etc/systemd/system/multi-user.target.wants/containerd.service → /lib/systemd/system/containerd.service.
Setting up cgroupfs-mount (1.4) ...
Setting up docker-ce-cli (5:19.03.8~3-0~ubuntu-bionic) ...
Setting up pigz (2.4-1) ...
Setting up docker-ce (5:19.03.8~3-0~ubuntu-bionic) ...
Created symlink /etc/systemd/system/multi-user.target.wants/docker.service → /lib/systemd/system/docker.service.
Created symlink /etc/systemd/system/sockets.target.wants/docker.socket → /lib/systemd/system/docker.socket.

which I need to suspend (ctrl+z) and then clean up everything again as described above.

Here's also a screenshot on how the systemd service looks while installation is stuck:

I have also tried to do apt clean and/or apt autoclean then reboot and try again, but nothing has worked so far, it still hangs when installing.