We user / have used Slack, Zoom, Meet/Gchat and a VERY brief trial of teams.
We have O365 AND Google Workspaces so we get teams and meet for free.
Zoom is the best to host a large meeting with a split presence. It's the best at dealing with variably poor connections. It shines on being able to share any specific app and sound control.
Meet is the best for small, low-friction meetings. However, it is hampered by its inability to share anything but browser tabs with sound, poor camera control, and poor user display.
Slack is a fantastic, too-flexible chat system with organizational issues. When it works, it works pretty well. However, it has intermittent video and mic problems on many systems. It is not good on poor connections and occasionally not good on fast connections.
Teams is bloated, many systems run it poorly, and there is an unacceptable amount of server-imposed downtime/issues.