People where I am from call everyone "you guys" - men, women, trans, doesn't matter, everyone is just "you guys" even when it's a woman addressing a group of women.
The literal meaning isn't gender neutral, but in actual practice, it 100% is.
As for "y'all" or "you all", I don't see how it could possibly be interpreted as offensive to any gender.
"y'all" fills a legitimately useful gap the English language has. Other languages have a word like this.
Edit: also something cool I just found out, some languages have a way to disinguish "we" (you and I), and "we" (me and the rest of us, not you). It's called clusivity and is missing from European languages. Many indigenous languages of the Americas and Oceania have this, as well as Vietnamese and northern dialects of Mandarin.
"Vous" is the first one that comes to mind in french. But since it is also a more formal (and/or "respectful") version of "tu/toi", it can both designate a group of people or a single person, depending on the context (just like "you" in English). Sometimes people will use "vous tous" (literally "you all") to make this clear.
It is a little better than the "you" situation in English since if you are speaking with someone that is not using the singular form of "vous" to speak about you (which is basically anyone you are familiar with unless they are your boss or In-laws and kind of oldschool), it is instantly clear what they mean at least.
In Portuguese (especially Brazilian), there are singular and plural forms of "you": "você" (singular) and "vocês" (plural). In English, "you" behaves like a plural because it's followed by "are" instead of "is". The only exception I can see is "yourself" and "yourselves" that refer to both singular and plural forms.
However, In Portuguese, even though we have "vocês" as plural form, we also use "vocês todos" or "todos vocês" ("you all"/"all of you") sometimes.
Y'all is the opposite of offensive for trans people. I lived in the south for a while, and I now use y'all specifically to be inclusive. I wouldn't say "you guys" is offensive to trans women, but I would say for me and likely other trans women it briefly brings to mind being misgendered in the past, so I would call it a small kindness to ube as gender neutral as possible.
(this is by no means exhaustive list, the point is there are plenty of existing and perfectly acceptable alternatives, pick one, or more, and get comfortable with it)
I'm not from the south and use "y'all" all the time. Find it very useful for filling in a gap that English has and slightly faster than saying "you all". Its gender neutral in my opinion.
I'll throw in "folks" as another gender neutral option. I say "you folks" all the time, especially in professional contexts. I'm not from the South, but I have family there so y'all is a part of my vocabulary. I use it in more informal situations pretty commonly.
I’m from Australia and I’ve started calling all groups of people yall because it’s gender neutral… very unaustralian term, and I love so much the irony of iconic southern terms being used to support trans activism
I'm German and I use y'all all the time when speaking English. it's funny, most of my English is from the internet so it's the most crazy mix of english
Why bother with importing y'all when we already have yous (or youse depending on how you want to spell it)? Or you could just treat 'you guys' as gender neutral, it effectively is these days with how people use it.
I feel like y'all is the newer American version of 2nd person plural, while yous/youse/yinz are the non-American English counterparts.
I have always used you guys in a gender neutral manner historically, but people occasionally got offended by that. So I started using y'all several years ago and it's been going pretty good. Although I did initially spell it like ya'll until someone corrected me on reddit 😅
I can't speak for anyone else, but you seem to be missing the biggest issue with this map: saying "you guys" excludes anyone but those identifying as male. You may not mean it that way, but I've had women be offended when I used that in the past, and I wouldn't like being referred to as a "gal" in a group of women. It's just not accurate.
Personally, for a gender-neutral way of addressing a group, I like "you folks".
English is not my native language. I felt kinda weird about using "you guys" until I heard a woman that used "you guys" to a 100% woman group. I stopped caring about that shit because natural languages are weird and it all doesn't matter. What matters is the intention of what you say, not its form. Y'all should stop caring about fixing other people's speech too.