IOS 26 bugs and issues

You are not speaking to Apple here, so they will not see your post. If you want to send feedback to them you can do that here and there is even an option to specify a bug report.

Product Feedback - Apple

Third party apps are free to use whatever they want as a keyboard. You see this especially in Meta apps where they also use their own Text Fields that don't support the features inherited by the standard UI controls provided by the OS. It is the developers choice if they want to adopt the standard keyboard and most of them do.

You can reduce the transparency of Liquid Glass if you wish, but you cannot turn it off. Go to Settings > Accessibility > Display & Text Size > Reduce Transparency.

It is expected your battery will drain fast and your phone will also run hotter than usual while the files are being indexed and the photos are being optimized for object detection algorithms. In addition you may see some UI actions appear laggy. Give it 3-4 days to finish and if you have a large photo library, maybe an extra day or two. That has been true for every major update, not just iOS 26.

About Apple software updates - Apple Support

You are not addressing Apple here. This is a user to user support forum. Feedback to Apple goes here, Feedback - iPhone - Apple

You're welcome.