Yes, in terms of gold things would be less valuable.
But choosing gold as the reference is arbitrary.
You could just as easily choose crude oil.
“Value” is a human defined quantity. Ultimately value is based on a person’s time/labor.
If it takes 1 hour of labor to feed ones family for the day that labor and food “value” exchange has little if anything to do with the current value of gold.
The point is, you could choose ANYTHING. Anything at all.
But, not just as easily. Your crude oil example is good. Can you imagine the inconveneince of toting around barrels of crude oil every time you went out for groceries or to have a nice meal?
You'll have to use certificates. There again, no problem. I'm sure it could be done and it would make a lot of sense in certain economies.
But we've been talking not about gold certificates, but gold itself as a medium of exchange. And on that count, gold excels for all the reasons I gave. The preeminence of gold is anythig but arbitrary. Of course you can use other things and historically, people have used shells, woven bits of cloth, other precious metals, and gems. Whatever you use has to have an intrinsic rarity and compactness, durability, concealability, and acceptablity in the market.
Gold outmatches anything else, and you won't find much of anything else used these days as an alternate to money except in socialist dogpiles like Ithaca, New York, where some people use labor scrips, just to prove their liberal credentials, and enhance their feelings of superiority.