On 16.04 keyboard shortcut Alt+f1 highlights launcher (same as super + t on Windows) then arrow keys left/rieght can go through icons to open hitting enter, see info if hitting menu, selct action from opened list in menu. This function is not possible on 20.04 ; similar is just super + number 1 to 9 opening corresponding app to the numbered icon. Any workaround ?
On Ubuntu 20.04, Alt+F1 opens the Activities Overview. The same is achieved using Super+s and also pressing and releasing Super.
The shortcut to directly go to the Applications overview is Super+a. Once you are there, you can use the arrow keys to move to the different icons, and PgUp/PgDn to move between the pages.
Once an application icon is highlighted, press Enter to run it. Hit Shift+F10 to see its context menu.
You could change Alt+F1 to show the applications overview rather than the activities overview in "Settings" - "Keyboard Shortcuts". Disable the existing binding of "Show activities overview" (under the "System" section) then change the binding for "Show all applications" to Alt+F1