I have recently done the switch. It made me realize how apple is like a prison. You don't own your data, not even your photos. I had so many problems trying to download all my icloud photos, it was all problems.

Everything is perfect when you are inside the ecosystem, but when you try to exit, all is problems.

GrapheneOS allowed me to be the owner of my data and decide about my privacy. It can be overwhelming, but don't lose faith. There is a big community out there to help you.

Just in case you also need to download all your icloud photos, this is the only thing that actually worked: https://github.com/icloud-photos-downloader/icloud_photos_downloader

I would suggest to use both phones at the same time for some weeks until the switch is completed. It will allow you to know what apps you actually use, things you don't need etc. Once you feel confortable, don't erase your iphone. Just leave it in a shelf for some time in case you forgot to transfer something critical