I personally find Teams to be an abomination. I asked my wife the other day, who isn't familiar with Slack or Teams, to look at the interfaces and tell me how to IM an individual. She glanced at Slack and pointed to the list of users. She looked at Teams and said "I have no idea". Slack practically invites me to reach out to people. Teams OTOH makes me want to send an email. Now you can add this tracking to the list…
So maybe Teams has a higher barrier of entry. I don't think that it's worse because of this particular reason.
Video chat and calendar integration work great, though.