This is a long time known and pushed away shortcoming that the root partition is way bto small.
We collected some links and especially this one here
https://together.jolla.com/question/222126/guide-installing-sailfish-x-on-xperias/#222126-33-increasing-the-root-lvm-volume-size
is a need to do for every one installing a bit more native applications.
Android apps are installed to home so will not help umstalling.
Try to drill down with e.g.
du -xsh /
where the real big data chunks are and go deeper and deeper.
I jad that earlier with JollaC and needed to uninstall lots of native packages i.e. big data apps like OSM scout or similar
…
Find out with e.g.
rpm -qa --queryformat '%{SIZE} %{NAME} \n' | sort -n -r | head -10