Hi @Jianxia ,
firstly, thank you for you respond.
Secondly, the reason to switch url states off is to ease the process of testing new Experience Builder app/widget while developing. If I need to refresh the app/builder to see the changes, the state is preserved. But in some testing scenarios it would be fine to have it always at its initial state.
So basically the reason is for testing/developing purposes.
Thank you,
Jan