This is not going to be popular, and may even be deemed offensive by some. I am not trying to insult or be incendiary. That said, this is genuinely my opinion.
I think that the common, modern uses of the terms “pansexual” and “queer” are often employed to solve a problem that does not exist: that “bisexual” is too limiting. Some argue that the “bi” in “bisexual” means that a bisexual person can only be attracted to men and to women, not to more fluid dynamics.