Ask the COBOL guys
There are people here who have worked in the same CF codebase for over twenty years. They might start and finish their careers in a language everyone else forgot about decades ago.
I think Ruby has enough momentum that career Rubyists will have a home for as long as they want one.
I spent 2 years coding in ColdFusion maybe 25 years ago. I've got experience!
Buddy of mine pivoted to doing just SQL and road into retirement as a DBA.
With hindsight, we both wished we had gone all-in on SQL way back when.
On my 50s, learnt SQL around 1996, have used SQL across Access, Informix, DB2, Sybase SQL Server, MS SQL Server, Oracle, MySQL, Postgres, PrestoDB, Neo4j.