All tests runs in English so there would be no problem if we continue using the hardcoded English strings, but if there are changes in those language strings we will need to update our steps definitions, this issue aim is to replace those hardcoded strings for get_string() calls, so in case there are changes in those strings we don't need to change our steps definitions.

To explain it a bit more, we hardcode text strings in our .feature files because we are asserting against those strings and they are part of the behaviour description, but when we have steps definitions like I log in as "username" (PHP code) we are also hardcoding language strings when we can perfectly use get_string() calls.