Not listening, for years.
Way back in the great and glorious days of Skype 6, Microsoft release version 6.22 trialled the UI that they wanted to push into Skype 7, and asked for feedback.
It was universally panned as cartoonish, huge, and annoying. We complained, loudly. Their response was to close the feedback forum, dump all the feedback in the sea, and press ahead full steam. (I pulled all my feedback into one blog post at https://moteprime.org/article.php?id=59 which has therefore survived.) Many users stayed with 6.21 until it was finally retired and they were forced to downgrade. At least 7 had most of the options and functions available in Skype 6.
Skype 8 is this nonsense again, on steroids. When it first came out, I took a look, and immediately switched back and forgot about it. So did many others. Only when we were threatened with a compulsory "upgrade" was there real push-back.
The current version is still huge, has no meaningful configuration options, does not support multi-window (although it's coming real soon now, honest, according to Chief Designer @peterskillman on Twitter) and still has massive gaps in essential features.
But it has all new emojis! They're 4x the size of the old ones! And you can't turn off the animations! Hooray! For anyone who wants to use Skype for something serious, it's a UI disaster.
Network effects tie us into it, but that can't last forever. Network effects can lock you in, but only up to a point. After that, they lock you out really fast. Look at how quickly MySpace fell out of favor once a critical mass of people started migrating elsewhere.