As a security engineer, I always cringe when anything involving containers is referred to as "serverless".
I always thought that one of the advantages of going serverless was that you didn't have to worry about keeping the underlying operating system up-to-date. No needing to do a monthly "sudo apt update && apt upgrade" or whatever. But containers throw that all away when container images enter the world.
Instead of updating your operating system, you're updating your images...and it's basically the same thing.