I'm not quite sure what exactly you were expecting from your success manager? They do provide pretty good insights which are not "rumors" and are always available to help you out (talking from personal experience). Their job is to tell you what you need to do to optimize your profile and earning potential on Fiverr.
Although, I have interacted with my Seller success manager only twice. Once via email and once via zoom. It definitely helped me alot and I actually never needed anymore dedicated support. For me, the much glamorous side of a Seller Plus is those amazing insights we get and I believe $29 is a very fair price for the value "Seller Plus" program provides.
So, I would advise you to enroll in it (if you can afford) as once you get used to it, you just can't go back.