Uhuh. Let me know how that works for you, out in a real corporate setting.
In my experience you can say all you want (if you’re lucky), but in the end, switching providers on a large scale costs a lot of money. And their money is more important than your discomfort.
You can either pick a battle that you cannot win (assuming you’re not the one in charge of the many millions such a migration would cost). You can just deal with it, or you can look for better circumstances.
You say you’re convincing people, management sees a trouble maker who’s spreading unhappiness.
In my opinion, it’s better to save your energy for something where it can make a change, not a futile attempt at trying to make an institute drop Outlook or Teams, or whatever shitty software we’re talking about.
But hey, this is just my advice. You do you.