I completely agree - this is such a small change in the grand scheme of things yet we're still waiting. There shouldn't be something so basic that is missing or has us using different products because our base product isn't capable of doing it. That's crazy.
If I have a webinar, where I want audio or video, I should be albe to control if other recipients are shown or not. Even the chat, doesn't cover simple features that WebEx has had for two decades. I should be able to offer chat to only presenters\hosts but not to each other. The foundation items should not take months and months to get to Teams. Meanwhile, you're adding and consuming development time on useless features or rarely used features.