What’s a better alternative? I was a big fan of Teams back when I worked with an org that used it
Slack and Mattermost
Honestly? Even Discord, a game chat app. Teams just sucks.
Or matrix. Matrix is great.
Honestly the standard way should be that organizations host their own Matrix server. Then they don’t have to pay for enterprise Teams or whatever, and they control their data.

How? It can’t even handle copy/pasting text without fucking up the formatting.

Creating new SharePoint sites whenever you start a chat so that you have a whole new way to lose your documents?

Better alternative? Pretty much any other chat app.