Most of the time I'll reply at least once. Then I might just end it after that. But I actually just realized this morning when I texted a friend that I completely forgot to reply to his text from yesterday.

Sometimes I'll mean to reply but I'm doing something and then I don't remember until I see it again much later/the next day or whatever. Not even sometimes, this happens with me A LOT.
It also depends how good or pointless the text is.