It’s so funny. My company is basically merger hell and we have both Teams and Slack for similar reasons.

One of the more important acquired companies with a cash cow product basically refused to move to Teams because they hate it and concocted a reason that we just had to keep it.

The reason was total BS but it was crafted to appeal to the higher-ups, and it worked, because nobody was really going to fight over less than ten bucks per person per month.