Granted, a lot of people who say they’re bisexual are probably actually pansexual, but stick with the label that is more widely used and understood out of convenience.

Yeah It's easier this way

That is not true, and never has been. The dichotomy described by bi in bisexual isn't male/female, it's homo/heterosexual. Pansexual is a subcategory of bisexual, emphasizing that one is attracted to all genders (or regardless of gender), not just a subset of them, equally. Whereas a bisexual might have varying levels of attentions to different genders

Historic definitions only matter in historic text.
The currently popular definitions are "attraction to your own and different genders" and "attraction regardless of gender".