How can I replicate this drywall texture?
That looks to me like a texture that developed over the years, inadvertently, with application of multiple layers of paint using a nappy roller.

You could try to duplicate by spray texturing in a "small blot" pattern, then knocking it down with a low nap roller. There are probably other ways... maybe a stippling roller would come close.

Bottom line is there is no way to really perfectly match any texture. Even pros need lots of practice and trial and error...