When you have absolute freedom to design the emails around the limitations, sure, that works and is certainly much better than the soup of tables and IE11/Offic

When you have absolute freedom to design the emails around the limitations, sure, that works and is certainly much better than the soup of tables and IE11/Office stuff. However even with that you still gotta test on multiple clients. If you want to use something like border-radius, for example, it won't work on some versions of Outlook, for example [1]. You either show a slightly different layout or you use workarounds. There are plenty of other examples like that. I personally just use very simple emails, so it's <p> and <h1> etc. But other people have to work around those limitations, and not everyone is a developer with design knowledge that can tweak the design to a point where it is both simple and good looking. [1] https://www.caniemail.com/search/?s=radius https://www.caniemail.com/search/?s=radius