I would distinguish between providing a service & creating value. the service that banks and insurance provide is useful, but only in the context of a money-centric society. they don't create anything that has a purpose deprived of context, it's only the moving around of numbers.
not exactly what you're asking, but banks and insurance companies are the majority of what I call "the beaurocracy of money". they don't produce anything of value, and are basically just a sinkhole for labour.
I think having some form of "I agree with this" or similar helps to make you feel engaged with the content (for better or worse).
I think perhaps the actual person responsible for the post or comment shouldn't be able to see the results, though, otherwise it just becomes another ego building thing, and you see people strategising explicitly to build karma like on reddit. instead, the author should see a rating, like "slight approval" "mixed feelings" "strong dissent", etc.