The new top bar of a page (with the three buttons, the page title and tool bar) now looks exactly like Apple Notes, and many of the other Big Sur apps. One of the draws of Bear is that it feels more like a writing app without a title bar, and the tools along the side are helpful and clean. I sincerely hope that there is an option to lose the top bar and instead put the tools on the side when Panda becomes Bear.
You can already do that from menu. View → Hide Toolbar