The comparison with as + positive + as indicates two or more persons or things of equal quality.
Examples of the comparison with as
In negative sentences as + positive + as is often replace by so + positive + as.
Examples of negative sentences comparison with as / so
She is not so beautiful as she’s sister.
She is not as beautiful as she’s sister.
Your car is not so good as ours!
Your car is not as good as ours!
We are not so happy as they are!
We are not as happy as they are!