If instant “coffee” tastes the same to you as a good, freshly ground Sumatra then your taste buds are far less sensitive than many people’s. In fact, that degree of sensory deficiency just screams dysomia .
To me, instant coffee tastes like it was mixed with pool cleaning chemicals. There are very few things I cannot drink even though some of them make me wince, but instant “coffee” is one of those things and I’ve drank some pretty disgusting stuff in my life. Even the coolant we use in our CNC machines at work tastes better than instant “coffee” as far as I am concerned.
Whether instant “coffee” is better-tasting is a matter of opinion (and I think I’ve made mine clear) but if you honestly can’t tell the difference then I suspect that you have medical issues. No joking; see a doctor about that!
However, if you actually can taste the difference but just don’t find it worth the extra cost then all that means is that you are more frugal than many people. I would rather pay more for a cup of coffee than drink the stagnant dishwater that some people think is coffee, but that’s me.
(For the record, I prefer home-brewed, freshly ground coffee, usually a darker roast. It tastes good (often better than a coffee shop’s) and isn’t nearly as expensive as a drip coffee at Starbucks.)