I know that I can subscribe to any thread I post to, but often enough, I don't want to. The threads in my "Subscriptions" folder are the ones I consider to be important for whatever reason, and which I want to keep monitoring even after a week or two has passed. If I subscribe to every thread I've ever posted to, this tool will get too unwieldy if I want to find something specific that hasn't seen activity in a while. I know I could always unsubscribe from a thread once I no longer want to monitor it, but that takes unnecessary time.
This is precisely why I liked the old function, because I could also keep abreast of threads that I didn't think were important enough to subscribe to, but which were interesting to follow anyway. I greatly preferred that solution to the mess we have now.
If you use the
Subscribed Threads in Folder: Subscriptions instead of "My Threads" you will get a list of all your subscribed threads with the ones with newest posts to them on the top. Provided you use the default setting to automatically subscribe to any thread to which you post, you'll get what you want. I've been using this feature for years to see what threads have received new posts since I last refreshed/reloaded the page, since they're on top and in bold type. I keep one tab open with this list and another for each of the forums I regularly visit.
There is no time lag on this list either, which means it refreshes/reloads in real-time, as does a forum index. The time lag is more of a problem for moderators and administrators, using the search by user, than for the general FTer.
EDIT: BTW, if you click on the link inside your post, below the "Posted By:" link to the user, it will take you to that (in this case your) post, rather than the first post in the thread. - Sorry that works in the "My Posts" search not the "My Threads" search.