Indeed, I'll believe a company isn't up to some repugnantly slimy shenanigans the moment they volunteer to accurately and carefully explain what data they want,

Indeed, I'll believe a company isn't up to some repugnantly slimy shenanigans the moment they volunteer to accurately and carefully explain what data they want, why they think it's useful, how they'll look after it and why it's in my interest to opt in, all without being threatened into doing the very barest minimum by law. Otherwise it's about as convincing as the school bully being forced to shake hands with his victim while the head teacher is standing over him.