Is link exchange worthy ?

if you do exchange your website link with your relevant and highpagerank sites then it's really worthy.

Link can only worthy if it is related to sites nature, dofollow, use appropriate keyword then we can say that it is worthy.
Back links are so much important for a site because they convert traffic on it.

 It is essential to practice pure, correct SEO tactics in order to rank better in search engines. In my opinion link exchange is the best option to build backlinks. It is vital to do link exchange between websites in the same trade in order to avoid negative impacts. This method will definitely give you quick results.

I don't think link exchange is working anymore nowadays after Google updated its penguin algorithms which is about link spamming and well as link building through black hat seo techniques.

Link Exchange is not much effective.
Try to get do follow backlinks on high PR sites that are good to have for a site.

No, link exchange is not working any more. Only back links generation with the help of off page SEO techniques is good to increase websites rankings in search engines.