So what?
Sure, maybe the Googles of the world aren't building on top of meta's products, but I can tell you that a lot of startups are.
Does it make these startups vulnerable, to long term future legal action? Sure, but nobody is thinking that far ahead. What people are thinking about is how to get users and show off flashy demos to investors.
Instead, people are just pushing out products, breaking meta's licenses, and not telling people about it, while they attempt to get traction.
Strict licensing, without enforcement, is not worth the paper that the contract is written on.
So yes, it is still beneficial that the code is released, even with a bad license.