Oh, I'm sure it's not random. I bet there's a rationale for almost every change in every piece of software UI. These are not bullies making changes just to annoy me; I know that. I can even understand why they stopped supporting the old look & feel after a grace period. I'm a software dev too, after all.

But from the point of view of a random user (me), it seems bizarre. The Gmail team changed things for no apparent gain. I don't care about Material Design -- I don't even know what that is! All I know is that the immediately previous incarnation of Gmail looked less cluttered and felt snappier. I know it's not accurate, but sometimes it feels they make UI changes just to show the app is not abandoned, whether this changes make sense or not.

There are some nice things about the new UI: e.g., it's possible to take actions (such as delete) on a email in the inbox in 1-click. It's also that gmail now has lot of new things. e.g., snooze, integration with tasks which probably meant that they had to update the UI regardless.

In split view, clicking a message to view it also adds 'archive' buttons under the mouse. So viewing a message immediately archives it.

Even if you could type text and have it appear on screen in a reasonable time, the current state of gmail is /insane/.