Does anyone at MS actually use Teams, because if they did, they'd know that searching for something in an ad hoc Chat thread is vital.
Have all the f-n O365 integration you want, but jezz, get the basics down for a chat client. This is not new technology or practices, Teams is still missing basic features you'd see in tools from 20+ years ago.
David S commented
Can't search in just a single named Chat thread. It requires specifying users. How ridiculous, what if I don't know what user said it? Or looking for general location.
For example I know I said "XXX" but can't search for XXX because I can't even search for my own text.