Both of these issues come because our ancestors messed up changing the language.
Centuries ago, "thou" was singular second person and "you" was plural second person.
"Thou" got abandoned and "you" lost its original meaning to replace "thou" as the new singular second person.
"You guys" or "y'all" are simply attempts to re-introduce a needed pronoun.
So we get to fight sexism AND bring back cool anachronistic language? I'm in.
Australia has 'yous' for plural you. Yous is used exactly how you might think it'd be used.
Beware! Y’all doesn’t necessarily include everyone:
> All y'all is used in the Southern United States when a speaker wishes to include everyone being addressed. Y'all may refer to an indefinite set of members of a group, but all y'all definitively includes everyone in the group.
IIRC "you" was also the formal second person pronoun (like usted in Spanish or vous in French).
I think it's all just normal evolution of language. I actually think it's kinda neat how different English-speaking subcultures found different ways to reintroduce the pronoun.