I find it's more about who I'm talking to and what it communicates than anything else. With cis, straight people I might identify as a lesbian even though I'm technically bi. I do that because I'm a woman in a long-term monogamous relationship with another woman, and it can be misleading or send the wrong message to say I'm bi.

Also cis, straight people don't tend to have much nuance in what they know about queer labels, and I don't want to be obnoxious and use language they are unfamiliar with - like, I may be technically "polysexual" rather than strictly "bisexual", but I'm not going to go into those details with probably anyone, tbh.

In fact, I try not to talk about my sexuality at all, but that's easier to do when I'm not looking to date new people, etc. For me sexuality is mostly private, I don't discuss it much with people IRL.