It isn't a conscious decision by me I think the non Hard option is the default.I notice plenty of posters are not on hard mode, is this so you can guess the next word not using a letter/ letters that you already have?
I think if you follow a set plan in easy mode to eliminate most obvious letters, you are mostly guaranteed not to fail. However you will not necessarily get the answer in less than 4.It isn't a conscious decision by me I think the non Hard option is the default.
I actually find the option a bit strange. Playing in hard mode is statistically more likely to help you solve the Wordle than the alternative.
I would be interested to hear the thoughts of others.