I've spent a full day attempting to send a webhook in. Teams used to work like slack (a channel admin can create an endpoint; you post to it.) Microsoft deprecated that because it worked. It's now a maze of permissions and it silently fails with no error messages at all.
Scrollback regularly fails and also requires app restart.
I cannot insert images into a channel w/ a customer via drag and drop, but I can paste them by opening them in preview, copying the image, and cmd+v into the channel. I wasted 4 hours w/ support trying to figure out why I can't drag images into the shared channel before giving up. This is typical of the Teams experience.
I could go on. Besides facebook's tools, it is the worst piece of software I've used and a demonstration of monopoly power to distribute total garbage. Slack has issues, but it does reliably do the core thing.