There's a lot of truth in that. Back in the day you could go to a wide variety brick and mortar places that no longer exist. Now every shopping complex, at least around here, has the exact same half-dozen chain stores. And, darn it, those places don't sell surplus military rifles!
My friend Shanghai McCoy pointed out that the -algia in nostalgia refers to pain, and given all the good things in my life that the passage of time has robbed from me, looking back can hurt.
On the other hand, while I do miss Monkey Wards, Woolworths and Sears, guns that were all steel and walnut and could be mail ordered and delivered to my door, I have to admit it's a good thing to have a cell phone (which I only use for emergencies -- yup I'm really old in that respect), a robot to sweep my living room floor, being able to source oddball stuff over the Internet and to start my day chatting with other like-minded geezers around the world such as yourself every morning.