During the 3.9 development period we will be working on an update to the Activity chooser. This is on the current roadmap (which you can see here).
We are looking at changing the size of the picker and making better use of the space inside of that, as well as adding starring / favouriting of activities. There is a newly created document with more details at https://docs.moodle.org/dev/Roadmap#Moodle_3.9_.28May_2020_release.29.
If you wish to follow along you can also view MDL-67255 which is the epic issue that covers all aspects of development for this project.