IDK. Camping can be very cheap. I went on camping trips all the time as a teenager and I had almost no money. Unless by "camping" you are talking about towing a small mobile home into a paved "campground" with electricity, water, showers and bathrooms.

I vaguely remember a magazine biography of an Italian scientist who lived near the mountains. In the summer, he liked to strike out on Friday afternoon with a hunk of bread and a hunk of cheese, think about scientific problems while he hiked around in the mountains, sleep under his jacket, and come home on Saturday or Sunday. In his location he didn't need any more material wealth to "go camping" than he needed to stay at home.

It might be more the opposite, that only in relatively recent times have people been able to get away for a day or two without doing what we would call "camping." If you were a hunter-gatherer you'd grab a buddy (or not), invent some excuse like checking for game in the next valley, and rough it for a night or two. Now if you fuck off for a weekend you can check into a hotel or an AirBNB.

I think they were called "hunting / gathering" for most of human history.

Heck, non-working pets (e.g. herd guardians, vermin control, etc.) were nearly unknown until relatively recently, because who had the wealth to feed a non-productive mouth?

The average person throughout history did not have a refrigerator or global trade. Therefore any decline in todays society is moot.

It's more just what they had to do anytime they traveled longer than a day's distance. I'm sure that happened for pleasure, but a trip specifically to camp seems like something that is more relegated to the modern age where you can get to a destination easily without having to just camp along the way.