Google has recently started updating its Beta channel iOS version of Chrome, introducing a related setting option that allows users to move the Omnibox setting to the bottom of the screen.
Google is currently inviting users to test this feature, it is not clear when it will be open to all users. Interested users can open the iOS Beta version of Chrome, in the address bar open the “chrome://flags/#bottom-omnibox-steady-state” page in the address bar, enable the Experimental Flag, and restart the browser to see the option.