Yes, this is the answer. Ctrl-Shift-V does paste without formatting in Teams, I use it every day!

But why?

The default behaviour that's used by like every other software is different than that.

Seriously people who copy paste Excel tables to Teams are the majority?

Cannot they just add edge cases for stuff like tables and leave normal text alone?

I've checked Google Docs and Libre Office and they both use Ctrl+V for formatted paste, and Ctrl+Shift+V for unformatted paste (Libre office gives a menu to choose).

I cant check MS word as I don't have it installed, but it seems to me that Teams is closer to using the default behaviour here.

Google Docs and Libre Office are document editing software,

Browsers (but it may be due to lack of support in controls?), Text Editors like Notepad++, Notepad, Discord, Textboxes do not behave like this

Idk honestly.

While I do expect format to follow between excel/word, then pasting it to other apps not something I expect. That's really rare case where I've found it useful.

The most ridiculous situation is when you paste from docs to github and it creates screenshoot or some weird, giant xml that causes site to hang for 10sec

Since that I'm heavily against programs messing with CTRL+V

But I think this does match the default in other software. I'm sure if you copy/paste from Excel to Word the default would be the fully formatted table not plain text.