In general. If you have small bantams, in a mild climate and let the chickens free range daily, you don't need so much space.
If you have a couple of roosters, very active chickens, and big breeds this is probably not enough. And if you have long and cold winters you certainly need more coop space.
Often a too crowded accommodation's is the cause of stress and feather pecking.
In one of the articles in the learning center are guidelines for the numbers you can keep in a coop and run, and the roost space they need to keep them happuly and healthy (average).
I started keeping Dutch bantams in 2014. I had 3 young pullets and one cockerel at the end of the summer, but I also had a few chicks who died.
I couldn’t keep the cockerel in spring because he made too much noise early mornings. I live in a town. I gave him away after he fertilised a number...
Not my chickens. But the quality of their feathers do get less ‘sparkling’. And each molt the feather pattern changes a bit.
This is my 9+ hen Ini mini. .
And a one photo with one of my black Dutch (8+ yo).
They get organic feed most of their lives.