isn't it better for administrators to just lock the post for awhile, rather than delete it immediately?
It all depend on the content of the post, if a post is being locked, then its either a low quality content or the content had been discussed already, sometimes we can also discover that some threads were being moved to the appropriate board required.
But in case of deleted post, such occurs in some cases whereby the content were either spamming, shitposting or found with a malicious content that could be aiming for a possible attack or scam, the moderators are used to all these, when they sight any, they already know what to do accordingly.
Or isn't it more appropriate for administrators to apply any of the options of which includes to either lock the post for a while and delete later,
This is like doing a single work twice and there is no need for such stress or long process.
or arrange similar shit posts into a separate board and delete later, so as it acts as a reminder to others and to the creator of such post on the kind of post not to make and present?
Why spare a low quality content or spam post, for what reference? such are to be deleted ASAP to let the OP know what he is doing is not allowed.