Have you tried increasing the root partition size? Requires some use of the command line.
Here’s a howto: olf (Olf0) (Olf0) / SailfishX on Xperias · GitLab - which I used successfully on my Xperia X and Xperia 10.
And here’s another: Extend SailfishOS rootfs with a hidden, unused partition.-Oskar Roesler's Blog - which I have not tried.
There’s some discussion about the topic in Increasing the "root" LVM volume size and in Not enough space using sfos-upgrade. Where are packages stored?.