1) You can call someone in Teams. Sure, Google Chat has "Start Meeting now" but it's very passive. I know some will see this as negative but ringing has massive advantages around UX.
2) Chat, Teams will persist chat after meeting ends. In fact, depending on how you hold the meeting, it might dump the contents into chat channel so it's preserved in more open manner.
3) You can have visible meetings. You can start a meeting in a Teams chat channel so everyone can see the meeting is going on. It creates that in the office feeling of two people working on a whiteboard nearby that if topic interests you, you can join in.
4) Sharing Documents, Add Word Document to meeting, everyone is granted permissions. Done.
The fact so many Google Workspaces companies have Slack is just frustrating. You have these two products that barely talk.