Hmm, well that's quite interesting then, because the ability to notice nuanced flavours should have more to do with the
smell of food than whether the taste buds are desensitized or not.
If your sense of smell is still good, it is very likely that you do taste all of these things, and the problem is more one of attention. The simple thing to do is to train that. Simply eating more slowly and trying to focus on what you smell when chewing should already make the flavours noticeable to the brain. It is easier if your nose does not have to "compete for attention" with the other senses, so closing your eyes will help, as will being in a noise-free environment.
As for the taste, if you don't notice salty soup your taste buds are indeed likely t obe desensitized. But even if you "grew up" on food too rich in salt and sugar, that not a permanent thing. You could try a kind of "taste detoxing" month - reducing salt/sugar intake to essentials for a while by setting strict rules to what kinds of sugars are allowed. It's hard for various reasons, but it works - WheezyWaiter made a very entertaining and IMO "neutral" video showing his experience trying it[0].
So you should be able to address both if you want. I recommend it! In general, getting in touch with one's senses is an enriching and fun experience (not just for tasting food).
[0] https://www.youtube.com/watch?v=wBtslkL5nUA