Yes, its still worthy. But it should be done very precisely. It will boost up the rankings if you are ranking with the competitor strictly. But it has to be done appropriately. Directory submission should be done on that website that is worthy and has higher pr and should be in your niche. Make sure of making the backlinks from the reputed sites otherwise Google will consider it as the spam, and you can’t keep the rankings for a long time.
This way the website has to have content, which is the most important thing in ranking. You can have an extensive site with the best ranking and have only about 5-10% of the content on your website or the keyword is completely out of my opinion. So, even if you don't have big resources in the niche where you are ranking, make the content as awesome as you can and show it on the site where you are ranking, so that you can show that you are ranking in your niche. But, it's important. Now, I have said it a lot, but still it's important. So, do get in contact with all the reputed websites and send them your submission. Then, you will see how the ranking on the website has progressed in the search results after you send them your submissions. Yes, it will not be that impressive in a.