I work for an HFT (not Jane Street) so I am biased, but we (the HFT industry as a whole) are quite small compared to big tech.

I’d estimate the total global HFT revenue to be 100 billion dollars a year, which is less than Apple and a tiny percentage of all big tech combined.

what do you mean by bad? you want someone to be on the other side of every investment you make...for free? why don't you do this yourself?

There is a lot of value in markets being efficient and cheap to trade in. Someone needs to do the job. The cheaper the job is done the better.

Same goes for market making.

If someone is getting rich providing that service - great! Additional bonus is that it's usually very smart people getting the money.

How is this any more of an upwards money funnel than the prohibitively expensive spreads and commissions that hindered lay access to the markets?