How can I change the quality of photos on Iphone 11? Can the software be updated to change size of photos. Its far worst than Samsung.

The iPhone 11 Pro has a 12 megapixel back camera (iPhone 11 Pro - Technical Specifications - Apple). The photos should look sharp on a display with a resolution of 4000x3000 pixel, as long as you are sticking with the optical zoom range and the photos have been downloaded at the full resolution from iCloud.

You will however get blurry pictures, if you are using the digital zoom with a high zoom range. This is to be expected, because the digital zoom has to interpolate pixels. Avoid the digital zoom range and stick with the perfect optical zoom ranges 0.5, 1, 2. If you just want a section of the photo, use the crop tool, after you take the photo.

There are some options in Settings > Camera, but nothing that would let you explicitly change the resolution or file size of images.

If storage is an issue, you can try turning on Settings > Photos > Optimize iPhone Storage, this will store full-resolution images in iCloud, keep a small sized preview on the phone, and download them in full-resolution when required. Google Photos is also an option, offering free and unlimited storage while keeping a fairly high quality copy of the photos.