I have a different experience. It was bad before MS came in and got way worst after - except the icon. The icon now is way more slick! But that won't cut it...
Plus, I would never use it professionally since Skype (and MS in general) are the extreme low in regards to privacy.
The one thing that really bugs me about Skype recently is that it refuses to remember my login. Every time I want to login to the Windows app after a restart or update it doesn't log me in automatically.
There isn't even a "remember me" option on the login page, which I swear used to be there. Since my password is a 1Password generated secure password, I have to go look it up every time.
Are you sure you're not mixing up Skype, which is just the traditional voip network, and "Skype for business" (aka Lync) which is part of Office but a very different product?
They only have to do one thing, and one thing only: OPEN. IT. UP. Andi don't mean federation or blablabla: just make it as simple to integrate with as Slack is. Simple API endpoint, basic security and off you go. Boom, victory.
Skype was actually quite decent years ago. It appears that with every new version it became more and more of a bloated buggy piece of shit. I use it mostly to talk to friends. Havent gone more than a couple days without it seg faulting. I LOVE that quirky sound buffer loop that repeats 'hey u still there' 10 times over as the piece of bloatware crashes. RIP skype.
Skype on OSX looks much better now and I suspect if they're focusing on Skype instead of spending $8B, then you're looking at serious competition.