You, y'all (small close group), y'all all (larger, further group), and "all y'all" — Southeast Texas (coastal) dialect form that showed up about 25 yrs ago. I suspect it might've been there all along, but only became acceptable at that point?
Another 100+ years, and this'll be some solid grammar.
That has to be more than 25 years
I grew up in Houston saying all that in the 80s
Don’t forget you’uns or yinz!
I struggled with this when I was a school teacher. English lacks a good way to clarify you are addressing a group vs one person, which comes up a lot in a classroom. “Class, you…” is clunky, “You guys…” has obvious issues, and y’all or any other contraction is generally considered bad grammar. I generally went with y’all. Kids would laugh about it, but that seemed to help get their attention.