Thanks posting here in the Community! We'll gladly help you out.
The app shouldn't lag regardless of the size of the app data folder. It's possible that some files of the app files have gotten corrupted and are causing the issue. We recommend that you follow the steps listed here to perform a clean reinstall of the app.
It would be best if you try bot the MicrosoftStore version as well as the one from our website. You should also check if you have enough free space on your Windows drive for the OS to function properly.
Hope you find this useful. Keep us posted if you have any questions.