The post you are reporting:
Firstly, the question may be more correctly put as, "Who were these people?"
Secondly, they were as we all are, people.
[Leaving aside the fact that most that appear here are commemorated 'Officially' and semi-officially. Either by others in a professional capacity or by relatives or acquaintances.]
They appear here, to be ignored, or to satisfy much the same need as biographies in general.
As for, 'What impact did they have on the world?' I'm tempted just to wonder what you yourself Carole might be doing today if you were not reading this? And leave it at that, for the time being anyway.
P.S.
Some are part of the history of this world and of Kent in particular, in terms of honest-to-goodness dates and such and to the social fabric of Kent, England, The UK and the world. There is often a clue in the Clerihew.