Why is the GPU performance of iPhone12pro worse than iPhone11pro?

The same graphics program runs in the webview, and the iPhone 12Pro has 15+% more GPU usage than the iPhone 11Pro. In theory, the performance of the A14 should be stronger than that of the A13. Is it possible to increase the GPU overhead by 15+% just because there are more 45x96 pixels? The fragment profiling in XCode Instrument, please see the screenshot.