@julian and furthermore if I had attached an image of a dog to the post, you could not add the hashtag dog to the post if I had forgotten it.

you would need to comment that it was missing and then I would have to add it.

@julian but in the interface you still write it in into the same area as the rest of the text and it still counts on the character counter. #AsYouCanSeeHere

@quillmatiq @julian hashtags are part of the text which encourages people to use less hashtags so that they can write more actual text instead.
this also reduces the searchability because people cannot append appropriate hashtags that the original author might have forgotten.

if tags were a separate list they could be added to similarly to how we can add emoji to other people's posts and they wouldn't subtract from the space for the actual text.