It says something about the current relationship of large corporate apps and users when Slack makes an update - of particular annoyance is that the search bar at the top basically eats the entire border now making it impossible to move the window around unless you make the window sufficiently large - and my immediate thought is “this must have been deliberate in order to make sure Slack takes up as much of my screen as possible.”
It’s hard for me to think of a legitimate reason for how massive that search bar is and why it is so damn close to all the edges at the top making the window virtually immovable unless you greatly expand it.
It’s just malicious design as usual.
Use Microsoft Teams for a while and you'll appreciate how good you had it with Slack!