It's almost universally hated in the world of women's sport - many events and teams have changed their names over the last few years to reflect this, replacing "ladies" and "ladies'" with "women" and "women's". "Girls" used to refer to adult women is perhaps even worse: simple rule of thumb, sportswriters and others - if they're female and under 18 it's OK to say girls (though ideally, only use the term for females aged under 16; "young women" is better for 16-18 year olds), if they're 18 plus they're women. Pretty easy to remember, really.

I rarely get fussed over language anymore. Meanings and connotations vary so widely as to be practically infinite. I pay attention to intent. I know malicious intent when I see it.

Only when someone says it is a condescending tone

It depends on the tone/context.
If it were me addressing a crowd of women it probably wouldn't occur to me; I'd say "Hey everybody" or "Hey guys" ...or "Ya'll".
My huge peeve IRL is being called "Miss". Uhm, you're not fooling me or anyone else and it's not proper etiquette either when the person is clearly a peer, being waited on, or being addressed by someone clearly younger. It just tells me you're clueless, and that you're annoying me.
I've not been a "Miss" in 20 years.

I really don't care. Call me something I don't like, and I just won't answer. Or I'll tell you exactly where you can go, and what you can do to yourself once you've arrived.

Meh. Just another assumption.

I may be a bit thick but what term would you like?

No

Can I ask why?
I'm not trying to be an ass, just curious.

Nope

My former husband came home from work all wigged out and asked me what was wrong about using the word "girls". I told him I would start referring to him as a "boy." ...........crickets.........

Don't miss him at all!

My bad, I use it often, as a term of respect. I grew up in Oz in the 60s, it was still a little British and we used "Ladies" when being polite.

Yes. And because I live in the south, ma'am is another popular one that I loathe hearing that everyone at work uses. I know ma'am is meant to be polite, but ugh..how about just using my name instead of an uncomfortable, unwelcome label or pet name (my name is ON my name tag, if people bother to read it)?

As with any words, to me, it depends upon the context and tone in which those words are used.

the tone (as in inflection) makes the music, as we'd say in germany.

living in oz now, i learned to appreciate the funny, because disrespectful addressing of a group of men as "girls", not be offended when being called either one of the "guys" or the "ladies". it's the intonation that does it. for that reason i drew the line when my landlord kept calling me "fraeulein" instead of by my name. condescension - no way.

Ma'am has always been cringe worthy.

It doesn't bother me too much depending on context. However, I do remember taking some kind of anti harrassment training back in the late 90's that forbade the term "ladies" as it could be interpreted as being short for "ladies of the night". It seemed a bit out there at the time, but it is interesting in relation to some comments below about how "ladylike" means higher status, not lower.

Wow....I never knew
any of this

I address groups of women as "ladies." Would you prefer I said, "Good evening, Women?"
Or, "How are you women tonight?" That sounds creepy, to me.

Me!

Trigger Warning: Snarky Irony Ahead

Sorry, couldn't resist.

No -is girls inappropriate as well?

Oops. Guess I'm in trouble. I've used "ladies" out of respect, I thought. So what should I say? Not ladies, not girls. And not dames or broads either, do those even exist? So what do I say? Women?

Not at all. I've been in sales for 50 years and I always address my customers as ladies. If they're very elderly (octogenarians or older) I use the term ladies or girls. It's 100% a matter of perspective. I'm a child of the 50's and I don't believe I've ever had any customers who are insulted, annoyed or offended by the term. Of course, tone of voice, when I greet someone, is very important. A perky "hello ladies!" works with any age group. Yes, even teens! Regardless of the greeting, it's acknowledgment of the customer's presence.