1. Replace the menubar with a hamburger menu; in some cases the hamburger menu then contains file/edit/&c. so it's just a spurious extra click
2. Require a click to see the contents of a submenu and a click to go back
Fortunately my most-used GNOME application (Evolution) has an option to restore the old behavior for both of those, but I literally cannot think of the motivation for these two changes that clearly make things worse. The only halfway plausible idea I have heard for #2 is that the GNOME UX designers think that submenus are bad, so if you make them hard enough to use, developers will stop putting them in their applications. #1 is probably partly a looks thing, and partly a "too many people have fewer horizontal lines on their screens than I did in 2004[1]" thing.
1: That's when I got a 1600x1200 monitor; people today with 1080p screens have only 56 more lines than the 1280x1024 monitor I had been using since the previous millennium
It’s unfortunate because in other ways I find GNOME/GTK more agreeable than KDE/Qt (layout of controls within windows is consistently better in GTK environments/apps for example, Qt apps have a tendency to feel slapdash/haphazard/“engineery”) but I don’t like the increasingly strong mobile influence.
My alternative to the menu bar would be a search bar that allowed me to search in a Google style everything related to that program: functions, features, shortcuts, and documentation.
File | Edit | View | etc. is not the right choice for every program.
Most would be better served by surfacing the most commonly used screens as tabs and most commonly used functions within those tabs. Ideally 2-4 taps is all it should take to get anywhere, and there should only ever be a tiny handful of niche things that take 5+ taps to access.