It doesn’t make sense to post solutions that don’t pass. The authors sometimes write alternative solutions but generally the solution provided is the most efficient and instructive. You can read the comments under the editorial for more information.

I think what you mean is, "To come up with a solution, sometimes you need to optimize the brute force solution step by step, so why doesn't the solution contain such process?"

No, it's not supposed to. An editorial is just a place where you can find standard solution to refer to.

Nop they aren't. it's the one the author of the solution came up with there will be codes way shorter, easier to implement/understand solutions probably