Apart from the advantage of instant preparation, to my undiscerning palate instant coffee has got all the qualities and taste of coffee I enjoy, and not being a coffee-connoisseur, I can't be disappointed by its apparent blandness or one-dimensionality.
And, for all the areas where I have no particular expertise or discerning taste, I can just enjoy the cheapest and most easily available version of that thing. It's awesome!
Take chocolate for example: at this point in my life, every piece of chocolate I eat is a treat, and when I'm with someone who just can't eat cheap chocolate (Hersheys) my reaction is "sucks to be you, nom nom nom". If I went down a rabbit hole where I could only enjoy a subset of all chocolate, I'd consider that a worse situation than being able to enjoy all chocolate.
I think people believe there is something like a magnitude of enjoyment, and when you are an expert eating something you consider perfect, you enjoy it more. I think that's probably dead wrong, and nothing has empirically disproven that for me. Certainly in the long run you'll enjoy fewer things than people with no (supposed) taste.
I do all the up-thread recommended coffee steps (good, fresh beans from a small local roaster, grind myself, etc.) and I love it. But in a pinch, I will drink crappy gas station coffee. It's not great, but it's...fine.
Similarly, I love high quality beer, but Coors light has it's place and is perfectly fine for what it is.
I have apparently managed to raise my ceiling for what I like, without needing to raise my floor for what I can tolerate.
Everybody tastes things differently because we each have a different subset of scent receptors, but for me, it's not that instant is bland or one-dimensional, but that it actively tastes bad.
Now I drink coffee with a lot of cream (but no sweetener), which is kind of the same idea. My pallete has matured enough for me to prefer not to have k-cups, but not much further than that.
But I still really like good, black fresh-ground coffee, don't like a lot of restaurant coffees without adding cream, and can't stand instant.
What this guy actually wants is cold brew. Served iced or cold, much muted bitterness/sourness and smoother, more coffee-forward flavors
The thing that's also nice about cold brew is that it's one of the most approachable ways to make a really good coffee. I have a $18 cold brew pitcher I bought on Amazon that is essentially just a filter that sits in water. Makes cold brew of equivalent or better quality than the coffeeshop down the street.
About the only two limitations of cold brew are that it takes 12 hours to make and that you need to water it down because it's essentially a needle straight into your caffeine vein. But heck, even with the 12 hour limitation, some crazy people managed to invent some device recently that is somehow able to make cold brew in like 5 minutes. I don't even water my cold brew down anymore, I just make it with half decaf beans and half regular beans and it's perfect.
Good beans make better cold brew, but bad beans make much better cold brew than they do hot coffee.