I am really not sure if I'm holding it wrong, but whenever we try to collaborate with a customer using teams, it's a huge pain.

It MIGHT be because we're not using Office 365 ourselves, but honestly: I don't care.

I've never had anyone complain about "I don't understand how use you slack guest account", but with teams it's nearly always a huge pain. :-(

(Don't get me started on Azure Devops.)