What I really don't understand is, how are these ads so lucrative, I can honestly say I've never bought a single thing because of Instagram or FB advertising, I

What I really don't understand is, how are these ads so lucrative, I can honestly say I've never bought a single thing because of Instagram or FB advertising, I ask people around me and they either don't even use the platforms anymore or feel the same. Maybe it's getting me subconsciously and my whole life is a product of Instagram algorithms ? What is going ? I'll admin my partner has promoted products on Instagram before so I guess there is her answer, but honestly, she found it pretty much useless in conversions and ultimately found much better success via other channels. Why these companies valuations are so high I have no idea, but I kind of thing in a more just world, they'd go bust.