Interesting. The only button I have in a 1:1 GChat is a video camera with a plus in the middle, and it simply creates a google meet link which I then send to the other person, and then we both join that link and are talking. The MS Teams functionality was more like a call - I hit the button, and I am in a video chat, and the phone is ringing on the other person's end. Maybe it's just my org's config but I don't have an equivalent function in GChat.