Massive FPS drop and lag on iPad 6th gen after new UI update in 1.21

After the introduction of the new user interface (UI) in version 1.21, Minecraft became almost unplayable on my iPad (6th generation, iPadOS 17.7.8). Before this update, in version 1.20, the game ran smoothly with 60 FPS. Now it struggles to stay above 15 FPS, even in the menu or in flat worlds.

I have already reduced all graphic settings (render distance, fancy graphics, smooth lighting, clouds, etc.), restarted the iPad, and closed all background apps — no improvement. The new UI seems to cause a heavy performance hit on older Apple devices.

Please either bring back the old UI, or provide a way to switch back to the classic interface for better performance. This severely impacts gameplay experience.