Extracting value from the market as they do it and leaving everyone operating at normal time/capital scales with less. Or isn’t that what you meant?
Yes, when you correct a mispricing in markets that is a valuable service and you tend to get paid in proportion to the mispricing you correct (this is why markets work so well, they provide dynamic incentives in a decentralized way).
In case you aren't aware, a world outside the US exists on different time zones and also invests in US capital markets.
Having 24/7 trading a massive value-add for the entire world who also invests in US companies, which benefits US companies tremendously given they will continue sucking up the world's capital.
This is yet another reason why global companies will continue going public in US markets instead of their own. Meanwhile Europe will continue struggling to form a capital markets union over the next 50 years while they slowly translate legal documents back and forth to each other in 42 languages, growing the fine dining economy of Brussels more than their domestic economies.
That's one way to think of it.
The other way to think of it is that these parties are essentially middle men who make a cut of the difference whenever someone buys/sells far from market price.
Basically if you mis price something they screw you rather than the counter party who would be interested in taking the other side at market.
I think this is stupid and does not add value, but I don't think it's harmful. It's like the stocks equivalent of a junk flipper.