I got invited to join national honors society but I decided not to do it because you're kinda expected to do a lot. It sounds stressful to constantly have to keep your grades high and fulfill the other requirements they set for you. It sounds hard to manage on top of everything else you may have going on in your life.
However, to some it may be worth it because it sets a great image for you especially if you plan on going to college. By keeping your grades high all year long you'll get benefits to college and are more likely to get accepted in wherever you want to go. It's up to you to decide if it's worth it or not.