Bi chicks are so boob-crazy it's hilarious as hell to listen whenever one talks about them.
As a bi-chick (and yes, I know I'm a sample size of one), I
do appreciate the booba.
Though my type tends to be skinny/athletic regardless of gender, so most of my girlfriends have had small chests. The thing that really makes me melt, though, is a girl with a six pack, which generally means small boobs. But at the end of the day, I'm like a guy, as long as there's boobs, big or small, I'm not complaining. I do prefer them to be proportional, though.
I suspect that one of the main reasons for why Millennial men often dislike large breasts is because we grew up in the 90s and basically 100% of porn stars back then had gigantic, monstrous, fake-as-fuck tits while the girls in school that we all crushed on looked nothing at all like them
The fake/real thing is not a huge deal to me personally; few women will advertise having augmentation since there's so much stigma attached to fake boobs, but there are a lot of women out there with modestly sized implants. I don't think oversized bolt-ons are as common as modest augmentations, but the bolt-ons are the ones people tend to notice. There have been times where I've been able to tell a woman has likely been augmented in porn pictures (what can I say, I'm a connoisseur of art). The trend I've seen in the comments, though, is that men tend not to complain unless it's quite obvious. Either because they can't tell or it doesn't bother them.
There are also some reasons beyond just being a lesbian/bisexual that women enjoy bigger boobs. At least in my experience, people notice cleavage, and it definitely gets me attention. Even the most mundane t-shirt on a small chested girl can look sexy/scandalous on someone bustier. Though there are the obvious downsides, too. But those with big booba privilege don't talk about that!