The Pidgin OTR plugin worked really well over many years, but I haven't used it in a while: https://otr.cypherpunks.ca/
Although IIRC Pidgin also stored network credentials in plain-text file. Maybe that has been resolved in the past 10 years?
So rather than a reversible cypher they leave it plain so that their users will freak out and /not/ share their files with folk and will properly lock down their creds file.
It might be due to Pidgin's age but in modern programs storing this data in plain text should be a last resort for systems that don't do secret management for you.