People enter these transactions because there's something in it for them, even if you think it's too little.
If people are systematically taking deals you wouldn’t, there might be a broad societal problem (why is tht crappy situation anyone’s best option?) or an information problem (why don’t they know better?) but the business offering the deals is probably not a logical or useful target if you want to address the larger problem.
That depends entirely on the definition of "value".
If a business exists solely to move money/stock around, that action does not create "value", in the sense that juggling oranges does not create "value".
Trading stocks is an effort to take advantage of the fluctuating relative value each stock has, so that individuals can take home the "profit". Such "profit" is not created, but sifted out of the economy. Is that 100% worthless? No, but it's darn close.
This is silly wishful thinking. There are plenty of businesses that are sustainably built on screwing people over or simply extracting money from them.
> What value are financial services?
I don't think he's talking about financial services like retail banking. I think he's talking about HFT activities other than market making. Legal front-running, etc.