When I deleted my app it deleted ALL my worlds

I kind of have 2 bugs/suggestions. My friend and I were trying to transfer a world to my app so i could use it without him having to AFK. So we got almost to where it worked but then hit a roadblock. I tried deleting my app and when I got back ALL my worlds were gone. I was working on a creative world that I had spent about a week just making a city and now I was adding to it and it’s gone. This is so frustrating that it deletes all the worlds when especially when you log into your Microsoft account and you click save to Microsoft IT SHOULD KEEP THE WORLDS. Please make it easier to transfer worlds and make it so that deleting the app DOESN’T delete your worlds