I don’t think “greed” is quite the right word. “Greed” would be the right word if they were trying to make themselves more profitable.

I mean regardless of whether it's greed or not it's happening because they need to generate a profit period lol.

“Why do investors invest so many hundred of billions of dollars into companies that cannot be profitable without becoming super-shitty? And why do users join them knowing that they’re going to become super-shitty one day?”

David Harvey has been ringing the bell on this for at least a decade lol. Effectively capitalism runs out of profitable investments when you need continued YoY growth. Like finding trillions of new investment opportunities a year is just not realistic. So capitalists fund bullshit projects and flow their money into markets where the perceived value is significantly greater than any of the actual socially necessary value. And that distance grows greater over time, until people realize 'what the fuck are we funding' (like what happened with crypto, or the metaverse), and then that gap immediately shrinks and the unlucky capitalists lose their money. And that will continue happening.