First, let me say I am a member of the GS Club.
GS was formed as a club with members taking part in locally organized rallies and other get togethers. Primarily a club of like-minded campers and RVers. The name Good Sam implies people being "good Sams", people helping people.
GS evolved into a larger organization offering roadside assistance, vehicle insurance, extended warranties on your TT or MH, and medical assistance at extra cost. However, each of these is available to non-members under the same or sometimes different names. I'm not sure of the discount members receive versus non-members. Also, GS issues several publications which may or may not be useful to you and are also available to non-members. The RV Travel Guide is useful for locating campgrounds while traveling. Also, you will receive four issues per year of Trailer Life or Motorhome which contain an insert of the official club magazine. GS also offers an Action Line which helps people who have had difficulty with repairs or insurance or both. You also receive a discount on fuel and LPG at Pilot and Flying J stations and a discount on camping fees at GS campgrounds." If you list your vehicles with them they will alert you to any recalls on the vehicles.
About every two months or so, GS will issue a series of on-line coupons which are good for discounts on specific merchandise at Camping World. If your planning to purchase any thing, check these coupons before deciding where to buy.
So, there are benefits to being a member but only you can determine the usefulness to you. Membership is not expensive and, if you travel a lot, you'll recoup your money and receive additional benefits.
Hope this helps.