There will also be icomplete-vertical. Maybe not as good as community/userspace solutions, but many built-ins saw tons of usability improvements. Aside from one or two things, project.el now covers most of the important projectile functionalities. And magit is magit, but for simple things vc.el might be enough. Also the amazing Modus themes finally stopped my theme hopping.

In elisp side, the generic seq.el/map.el and new string functions are now almost enough to not need reaching out to "missing stdlib" such as dash.el/s.el etc.