This leads to brittle code - it's easy to determine if is_player_untouched state changes between those two conditions when writing the code but when someone els

This leads to brittle code - it's easy to determine if is_player_untouched state changes between those two conditions when writing the code but when someone else edits that code it's also easy to introduce something that will break it and the monolithic/big function makes it hard to keep track of assumptions like this and it leads to a lot of code changes in those big functions as well. Even worse this kinds of bugs usually end up being hard to test if you're not covered with unit tests, and games rarely are, and big functions go against testing practices.