why does it matter
More accurate ELO

SacrifycedStoat wrote: “This way, if a person selects a starting rating that is higher or lower than their actual skill level, people would know that it isn’t their real rating.”
That is important because ratings should be accurate and really new accounts often have inaccurate ratings.
I propose a solution: until a player has won 10 AND lost 10 games in a certain time control, their rating for that time control will have a ? next to it.
This way, if a person selects a starting rating that is higher or lower than their actual skill level, people would know that it isn’t their real rating.