Prefixes: Bi = Two | Pan = All | Omni = All

I'm not looking to start arguments; I'm just genuinely confused and sharing my thoughts.
and sorry if the flair is wrong, it was the best fitting one.

I understand that terms change over time or different meanings of words get more popular and accepted and told terms get thrown away.

As far as I'm aware, currently, Bisexual/romantic and Pansexual/romantic are just the exact same thing.
Even Bi being "Two or more" is being run out. When people ask what the difference is, I just have been hearing people say "There is no difference, it's just which ever you feel more comfortable being"

...When I was first learning about the LGBTQ+ community, I learned about Bisexuality. Bisexual was being attracted to two genders, as the prefix would make you assume.
Then as I learned more, and learned that there were other genders, I found Pansexuality which is liking people regardless of gender.
I also found Omnisexual which was basically Pansexual but with a preference.

Then a few years ago is when I started seeing Bisexual be referred to as "Two or more" and I was like... Okay. Two... or more... sure, I guess. There are a lot of genders, some people aren't bound to like ALL (Pan, Omni) of them.

But now... Bi is also all genders...? Bi and Pan are just interchangeable now ?
I'm just genuinely confused of why this is.

I went from identifying as Bi to Pan because I thought Pan meant to like people regardless of gender/you like ALL genders.
But now that's also what Bi is ? or at least that's what people are saying.

And if being Bi isn't just liking two genders, then what's the point of it being "Bi" ?
And don't say something like "Well, the prefix isn't always used to mean two !" because... it is ? You don't call a cycle with three wheels a bicycle still, because it's a tri(three)cycle now.
Same with being bilingual ? I'm going to assume you only know two languages.

Maybe it's just because I'm autistic and take things too seriously... but I'm genuinely confused where this came from.

It's not like only liking two genders would be transphobic ?
The only time where it would be transphobic is them excluding trans people of those genders they like.
But we don't call being gay or straight transphobic just because they're not attracted to a gender, they're... not attracted to ?
Transgender itself isn't a gender, is a term to describe the transition from one gender to another (or to no gender).

As someone who is genderless, I wouldn't take offence if someone with gender preferences weren't attracted to people without gender...
I don't understand having preference, but I know that people often do.
But that's where I thought a difference between Pan, Bi, and Omni lay. Preference.

Pan used to be "Hearts, not parts" or it was "Gender blind" for these reasons.
Now, I know that those phrases have their issues and they're not used much anymore for that but is Bi supposed to also be gender blind now ?

I just really don't understand...

I'm not trying to be "Biphobic" or anything... As a panromantic person, I'm always looking out for pan reputation. It feels good to be represented. And I often hear people complaining about biphobia in media... which I understand. But I still see more bisexual rep than pan. And I feel like that's going to be even more so if Bi and Pan just get pushed into the same meaning but with two different sexualities.

...If you read all of this, thank you. If I said something wrong, please quote it and tell me what was wrong with what I said. I'm not looking to argue, I'm just genuinely confused and want a civil discussion about this topic.
Thank you.