Service Station is the Mac app I didn’t know I was waiting for. It lets you customize the Finder’s right-click contextual menu to put essential functions just a click away. It’s also from the Mac App Store, and uses the official Finder Extension framework, so you don’t need to worry about running some weird hack on your machine.
Unfortunately, it only runs on macOS 10.14.4 or later, so I can’t use it on my old iMac. (That’s a sad-face emoji right there.)