i think narrowing down opinions on sexualities and genders to "do you think theyre valid" is nonsensical and meaningless. anyways, im not gonna go after random pan people or whatever, i dont care. but i do think its not worth the associations with the term to use pan instead of bi. if you arent a biphobe or transphobe and you believe pan and bi are the exact same, attraction regardless of gender, why keep using a term with a disturbing and horrific history and current bigoted use like that? like...pansexuality was coined by a horrific person to describe the attraction to all genders, as well as animals and children and corpses. it was later used to describe attraction to men, women, and trans people for the reason that it was used to describe attraction to everything. it was changed after outrage to be attraction to men, women, and nonbinary people specifically, like that helps, and now it sits at "its attraction to all genders" when bisexual is already that and you have to be extremely biphobic and greatly damage the bi community in order to make it seem different. you remember when people found out the creator of the lesbian flag was a t/rf, racist, anti butch, etc and everyone demanded people stop using it because of its problematic association? i dont understand why that isnt also applied to identifying with a term that is just a copy of another term and was coined by someone who was sexually predatory towards his daughter for being a lesbian, directly caused the r/pes of countless children to not be believed or to be believed that the children secretly consented, and literally coined the term itself to describe attraction to men and women, trans people (which was categorized separately), children, animals, and corpses. pansexuality was literally an umbrella term for people who were bisexual pedophiles, zoophiles, and necrophiles all at once. it was coined as an lgbt identity for that reason, it was used because of its usage as attraction to "men, women, and trans people" and the fact it was meant to describe attraction to "weird things most people arent attracted to" ie trans people.
tldr: im not gonna go bother pan people and dont care about this subject and wont talk about it unless asked about it, but since you did ask, i just dont think you should be using the term pansexual because all of its previous meanings were extremely disturbing, and its current meaning is literally just bisexual. i think people should try to really think about why they feel so attached to the pansexual label rather than bisexual if they understand that they mean the same thing