I had some issues installing MySQL Workbench on my Chromebook but ended up getting it working by installing a slightly earlier release.
I downloaded version 8.0.19 (Ubuntu Linux 18.04 (x86, 64-bit), DEB Package) and opened the .deb file from the Chromebook which then installed using GDebi.
GDebi install by:
sudo apt install gdebi
After installing Workbench I had another issue when setting up a connection and entering a password.
the name org.freedesktop.secrets was not provided by any .service files
This was solved by running the following command in the terminal:
sudo apt install gnome-keyring
After that everything worked 🙂