Do you mean the Pixel Camera app? You can install that like a normal app from the Play Store. I’m using Open Camera instead though.

Using GrapheneOS.

Vim is actually highly ergonomic; you can do everything with a minimum of keystrokes without moving a hand away to a mouse or touchpad or oven the arrow keys. If that’s worth the time investment to learn it, is a highly subjective question. But I’d say it’s a lot easier than many people think.