But those small clients also do not know much about WordPress and use nearly unlimited traffic hosting. It would be a challenge to explain what your plugin does.
You are right that a lot of those clients are on “unlimited” hosting and never think about bandwidth at all. I am still trying to figure out how big the overlap is between “does not want to touch Cloudflare” and “actually cares about image performance.” This thread is helping me sanity check whether that overlap is real or just in my head.