https://www.pcgamingwiki.com/wiki/Glossary:Game_data#Steam_client
The section above mentions `~/.steam/steam` as the default location for Linux. This is true, and there are more folders that contain client files.
Depending on the way steam has been installed and the distro the client has been installed to, the following directories might contain client files:
The most important ones are probably `~/.local/share/Steam`, `~/.var/app/com.valvesoftware.Steam/data/steam` and `~/.var/app/com.valvesoftware.Steam/data/Steam`. These should cover the most common installation variations.