Chrome 69/70 breaks fullscreen mode on mac. Whereas previously you could use a tab in fullscreen mode and hover near the top to reveal all the tabs, now tabs toolbar are either permanently visible in non fullscreen or hidden without a way to access them using the mouse pointer when you enter fullscreen mode.
This reduces screen real estate usability significantly as when you're multitasking you want to switch between tabs only on hover near top of screen and otherwise have the displayport filled with web content. There are LOTS of questions of how to do the opposite(show tabs when in fullscreen) but i prefer the described behaviour which is currently broken.
Show tabs in Chrome full screen mode? for example has only answers about using shortcuts to switch between tabs - this is NOT the behavior i want, i want to be able to hover near the top of the screen to display the available tabs and click on another tab to switch to it.