I'll actually vouch for the current state of Chat. The Google Chat and Spaces functionality included in the office suite is a great addition. It still has a ways to go to be anywhere close to the level of Slack, but what they have so far is extremely useful for customers that don't want to deal with an outside service. It's improved a lot in a short period of time.
I've seen 2 companies I consult with adopt it and it's currently "good enough" to bypass a need for Slack without all of the pain points of equivalent MS Teams.