Most apps leave data behind even after uninstalling, especially in windows. These two folders however seems harmless and are useful when the app is installed again. One is the working directory which one can use to share the cached local media files to other devices if required.If one forgot to make a backup of it, they can do so now. Another is updater cache, this might not be usable to many. But for some reason, if one wants to reinstall the app after uninstalling, they can use this instead of downloading it again from the website.
On the other hand, the uninstaller could present an option to completely remove any traces of anytype from the device though. There is one more entry used by anytype that is IIRC is also not removed after uninstallation - the windows credential entry used to store the keyphrase. I’ll check this tomorrow and will update this post