So we all know that when you reply to a thread, it brings it to the top of the first page. Well, I think there should be a way to bring it to the top without replying, if like it, but don’t have anything to say.

The bringing it to the top is a feature to bring attention new posts.
Your suggestion would just clutter things up.
(speaking as a layman)

You could just click the Notify option and you’ll find out when new messages have been posted. That works good for me.