Running Mumble server for my coworkers and instantly switching between channels is very effective. Where in Teams people are occupied to one meeting we can quickly help each other. Also created many one-on-one channels so you can talk privately if needed. It's free, very fast and low latency, scales to hundreds of clients on single server instance has text-to-speech notifications and multiple clients on Windows, Linux, Android and so on. The server can be very secure and private, if you combine Wireguard with Mumble and only bind to the WG0 interface it's encrypted twice. No centralized eavesdropping like is possible with Zoom, Teams. The attack on private conversations is real, see the freenode saga or Skype being bought by the mother of all telemetry etc.