[RhysU]

Define "meaningful work". Is it challenging? Enjoyable? Does it provide a good or service that someone wants? Can you support your dependents? Do you like the people you eat lunch with? Does it use the specialized skills that you have invested in learning? Check check check check check check.

Not sold? There are 168 hours in a week! Someone's raison d'etre need not fall into the 40 hours of the work week. For example, my job permits my spouse to pursue what she absolutely loves.

"Socially wasteful" is in the eye of the beholder. We probably have different values or philosophies. Let's just disagree.

You seem fixated on HFT. And you want more examples. Say there's some low-latency statistical arbitrage shop full of biotech luminaries that were sucked into finance only for the pay. And say they trade only to line their own pockets. And they hate all puppies and every single kitten. Real morally objectionable dirt bags. They're still (still!) trading with willing counterparties who wanted to trade that specific instrument at that specific price or per those specific terms. Every single trade requires two participants.

Hit me up by email if you want to talk more.