It is polarizing though. There are a lot of people who will get positively offended at the notion that their wireless earbuds are not perfect.
One of the things that biases is that they hear the others OK, so assume the earbuds are fine. What needs digging is to understand that when somebody has open mike like that, most meeting software engages heavy noise reduction or even half-duplex conversation; so there's a lot of interruptions and "what did you say" and garbled voices for other people, that is hard to trace to root cause of that open busy mike.
Oh man, the half-duplex conversation is terrible. If people start cutting off whenever someone else speaks, I tell them to wear headphones, but I really don't understand how headphones + push-to-talk isn't standard for everyone by now.
2. Cheerful regular person who thinks everything is great (*and doesn't really want to bother)
As well, it reminds me of how everybody believes themselves to be a great driver. Try getting advanced driving school gift certificate to a friend, family or special someone - they almost universally find it insulting and offensive. "I've been driving for 20 years!". (sure, what new skill have you learned or worked on in last 19.8 years?)
Similarly, no matter how kindly I suggest headset, I invariably hear some variation of angry "I do this for a living, trust me" or a strangely patronizing "No, this works great".
Hmm, the "oh you're cutting out, you aren't using headphones, right?" works great for me, because the accurate prediction of non-headphoneness is enough to make them believe that that's the problem.
The only thing better is an actual VoIP phone (eg Polycom).