You can upload photos to iCloud from your iPhone, iPad, PC, or Mac computer and easily sync photos across all of your devices ...
Choosing between iCloud Photos and Google Photos isn't always straightforward. Each has pros and cons that make the decision harder than it looks.
I'm not seeing reports of iOS 26 installs going sideways, but I still always take these steps before making a major upgrade.
To sign out of iCloud on all of your devices at once, you can head to iCloud's website and change your password.