The 'send' example perfectly illustrates why I would find Material 3 hard to use - it makes it harder to write the message but easier to send. It's less usable.
That's also my impression. They even brag about it. They have optimized the time that it takes to find the send button (something that I will only have to do once or maybe a few times until I get used to it) at the expense of a good portion of screen space that would be very useful when actually writing emails.