Catalina screenshot doesn't work

I've wasted a load of time just trying to copy a screenshot into an email. Something that should be, and always was very easy.

Now, for some reason I fail to understand, there need to be more options, and regardless what I try, I cannot paste the screenshot into an Outlook email. Outlook isn't the greatest, but it's used by loads of companies.

Even if the screenshot is saved to the desktop, I cannot paste it within the body of an email. Any reason we can't do something so simple?