Why do we say “open” and “closed”? Why is one in present tense and the other in past tense?

Question

Edit: to clarify, I mean when shops have a sign that says “open” versus “closed”. Why is it not “opened/closed” or “open/close”?

In: Other

Answer 1

My rational for closed being past tense is that “close” as an adjective has a different meaning, like “close call”
Why not say opened instead of open then? I have no idea