Is a camper more affordable than an apartment?

It depends where you live. Here, land is at a premium so the rent for a space that can fit a camper or prefab home would be higher than that for an apartment.

I have lived in a camper. I do not recommend it unless you live in an extremely mild climate. They are poorly-insulated, the windows fog up, they leak in the rain if you have slides. The hot water tank only holds enough for a 5 minute shower before the water starts to run cold. You have to deal with propane refills. The water hookup can freeze in the winter. Mice can get in easily. You have to stay mindful of the blackwater tank, because leaving it open creates a pyramid of waste that can't be removed, but leaving it closed means you have to remember to empty it. The power system isn't meant to handle a lot of things plugged in at once. When the DC fuses blow, you have to go find replacements at an auto parts store. The oven doesn't have a broiler. The fridge is quite inefficient and small. The list of issues goes on and on. Make sure you're really committed to the lifestyle.

Just remember campers usually aren't designed to live in long term so they can grow mold if you don't get enough air flow inside

100% yes. If and only if you have a place to park it.

If you don't have a consistent place to park it, it's going to be super stressful. So you have to factor that into the ownership cost

Depends where you park it. Here in SW Florida rv spots are $1500/mo with a waiting list.

I've daydreamed bout buying a parking spot to own in a city and live in a camper parked in it. Lol