Once the ProtonPass browser's extension is installed, clicking a password field will actually display the password in a popover.
I personally don't see any useful reason to display a 15 characters long password (which I won't even remember) to be displayed each time I click a registered password field.
More than that, this kind of feature prevent me to use the whole software since I know that my passwords will be leaked if I am streaming / being in a visioconference, or if I am browsing on my computer with a client / customer currently watching my screen next to me.
Since all the Proton's softwares are absolutely excellent in terms of UI/UX, I hope that a future release would allow to hide the password by default, and optionally allow the user to show the password by clicking a button.