Of the fruit I have had:
I wouldn’t say papayas are overrated, as many people seem to not like them (wasn’t there a thread on this recently?). Some are definitely better than others, and at their best they are a good, refreshing mild fruit. Not the best in the world, but fits its purpose well.
Dragonfruit is terrible unless it’s the yellow variety, then it’s quite good. I’d put a regular kiwi above it, but I have not had the freshest/best samples of either, so not sure.
Mamey sapote is okay, I don’t really like the flavor that much but it should make good smoothies/milkshakes. Not sure if it’s “overrated,” but it’s nothing spectacular.
Annonas: I’ve had three. A fermented supermarket (Virginia supermarket) cherimoya, a rotting soursop in Indiana, and 5 varieties of pawpaw. The pawpaws were definitely something special, with a very strong flavor and a huge amount of sweetness. I have to say they are somewhat of an acquired taste, and I’m still not sure if I like them, but the Susquehanna variety in particular had a more fruity taste which I enjoyed.
Jaboticabas I’ve tried once in Puerto Rico, and they had a very interesting taste, not sure if that’s normal and don’t know what variety I had. If they all taste like that, I can understand why people like them. Overrated? Based on the crazy prices you see for any “rare” variety, there is definitely a fad going around.
Guavas have a terrific aroma and flavor, though the supermarket ones I’ve had could have been better and the seeds were very distracting. But I can definitely see why people hold them in high esteem, I imagine one of those seedless guavas would be amazing.
Passionfruit is much too sour for me, but in a very hot climate it’s refreshing and good. Not overrated I’d say.
I realize this is getting long, so I’d like to finish by saying that most commercial “superfood” tropical fruits are overrated in the public’s eye, but can be quite good when of good quality and used appropriately. The tropical fruit community looks for “more” than the supermarket offers, and so you have more divide in what people like as the supermarket panders to the most people it can, while tropical fruit enthusiasts grow their own without these concerns. So, as most exotic and unknown fruit will generally have “different” flavors and textures, some people will love them while others will not understand what the fuss is about.