They represent different types of use. Yes, you can sleep or live in a tent, but the downsides have been mentioned already, as well as some of the upsides. I lived in a real old school 16' tipi off and on a couple years, they are absolutely awesome shelters, but do take real time and effort to set up and take down, and are bulky and heavy and require the pole set. Id still love to have another one, but its somewhat of a niche shelter and takes some knowledge and experience to do well. To me, the benefits are quite tangible, very roomy, very stable in all weather, can have an open fire inside, and are fun to use. Ive been in 0 deg temps and it was shirtsleeves comfortable inside with a fire going. I dont think the so-called tipi-tent that arent an actual tipi share any of the real benefits of a true tipi, they should be classified with common tents.
Ive also spend months living in a canvas wall tent, mine is 9x12 with 5' sidewalls and 8' ridge. With the metal pole set it withstood 80 mph winds fine, with the wood pole set, its easier and lighter to carry, but not quite as secure. Ive not had it in higher winds with the wood poles. Its very comfortable inside, when i spent several months in it I took a metal twin bed frame and mattress, small bedside chest, folding table and bench, and a carpet. I also have a folding sheet metal Sims woodstove for it. Its very nice camping in it if youre going to stay in one place a while, or even an overnight if you have time for setup and all. You can also have a fire in front of one to be out of the weather and still enjoy the fire.
Vehicle. Mostly just park and done. Simple, fast, more secure, not generally as roomy as the larger tents mentioned above. Ive only had pickups with shells and SUVs, so cant comment on the room in a van for camping. Vehicle camping is certainly less conspicuous. You can of course have a tent for times when you want more space, or for projects, day use, cooking, whatever. When I get back to semi-nomadic status I plan on a cargo trailer camper and will have my wall tent along. I dont think Id make it a car vs tent question, they both work but in different ways. Vehicle camping is more practical overall for most people and situations. A tent gives some more options, but i wouldnt want it to be the only option. In much of the areas ive camped in northern Az in the past I threw a tarp on the ground with my pads and sleeping bag and slept out under the stars. Its my first choice for decent weather, but wouldnt want it to be my only choice either. I spent about 5-6 years nomading around, mostly N Az, in a combination of tipi, off the motorcycle, out of the back of my pickup with shell, and out under the stars. All types have their appeal and use.