I've travelled and camped since I got my licence, my second car was a Nissan panel van and I travelled around southern Africa with it. I've drive over 50,000km with my Land Rovers with a roof top tent in Australia. I find that when the weather is good, when the roads are good, you don't need much to be happy. Life is easy, nothing to stress about and both my wife and I are happy.
When the roads or weather turn bad, then things get a bit more difficult. Camping with a tent for a weekend when it's raining all the time is pretty miserable, if it looks like it's going to rain for a week, we move on or head home. Setting up a tent every night and then packing up each morning is tedious. We then got a roof top tent and can set-up i pitch dark in 10 minutes. Packing up takes about 25 minutes. My Defender can go most places, have a reasonable range and is pretty comfortable. We have about 30,000km of camping trip over the past two years. There are quite a few time we have had to stay in a hotel for a night or two just to get some sleep. 30km winds, heavy rain, all make living outside your vehicle pretty miserable.
If you want to travel in remote areas, you need a capable vehicle. We drove down the Birdsville track after the floods, it was pretty stressful wondering whether you would make it through the next water crossing or get stuck for days. We met a guy who was towing a big caravan up the Birdsville track with a two wheel drive. He made it about half way, then it started to rain. He was there for two months - not my idea of fun. Diff locks and bigger MT tyres make the difference to me between hoping you will get through, worrying constantly about getting stuck or being confident most of the time and just enjoying the trip. We have found the limitations of our Land Rover. On our last trip we had our inflatable canoe and outboard, it took up a lot of room and added another 60kg. We were staying in a remote national park - 350km from the nearest fuel in any direction and it had about 200km of tracks to explore. Spending a week there we had to be careful with water, could not drive everywhere we wanted as we did not have enough fuel and just the fact that the Land Rover was very heavily loaded so we had to be extra careful not to break anything.
Each time we take a trip, we think of the things that we absolutely need, what we can do without, and what would just make it nicer.
I'm building a truck for travelling in Australia and then a round the world trip. My Unimog will be have a lot of luxuries by most people standards. We have a latex mattress on a slatted base, it's more comfortable than the on in my bedroom, we have hot water to wash and shower, filters for drinking water that filter out all bacteria and viruses, a fridge and a freezer to keep food fresh. We have space for all sorts of clothing, for all weather. The camper is insulated and heated for temps down to -20 degree C. It is important for us to have a comfortable weatherproof camper that we can park up in the middle of a storm and have a good meal and comfortable nights sleep. We will have a Nespresso machine for coffee, bread maker, nice chairs and tables for living outside when we can, nice chairs and table for inside when we have to. We can carry out boat with us, stay for two or more weeks without re-supply,
We want to drive in very remote place in Australia by ourselves. We don't want to worry about getting stuck all the time, we want a 1500km range, we don't want to worry about fuel range or lack of water. We want lots of ground clearance, to be able to drive through 4 ft of water without worrying, we want something that rides well on corrugations. We want something that can handle poor quality fuel without worrying, something that is designed to be off-road for hundreds of thousands of km. We are willing to put up with driving a truck, it might be a bit noisier than the Land Rover (I've added loads to sound and heat insulation so maybe not) it will be slow, it will use a lot more fuel, and it also costs a lot and has taken 4 years to build. I've enjoyed building it, I can maintain everything on and we have still travelled extensively whist still building it
Could we make do with a lot less, but why "make do" when you can be comfortable, why have to forgo driving down a remote track just because of lack of fuel or supplies or because the road looks a bit bumpy or the river crossing a bit deep We want to carry our boat, kite surfing equipment, bicycles, tent and hiking gear. Why be miserable just because it's cold and wet, living on the road is a lot different from a camping trip for a week or two.
The OP said he found he needed less and less each trip. We might not need much, but we've added the things we want and will leave behind the thing we don't want.