A lot of the time it's mostly just cost savings. However, on smaller ones there usually isn't really enough room. I have a Miata and my "spare" is a bottle of fix a flat, as there isn't really enough room to have a trunk and a spare (earlier ones did have one at the expense of a lot of trunk space). It's annoying and I do have a couple of spares I keep at home, as I have had to deal with flat tires and it's very annoying to be towed for just a minor flat. It is what it is, but I would prefer an option to add a tire occasionally for longer trips, like on a tow hitch or something.
Addv4
It really depends on what you want to do. If you're trying to build muscle, lifting weights and a little bit of cardio will make you strong and feel just generally better (less mental fog, have more energy, etc). You can generally get a good deal of the benefits if you're just starting out at home, provided you are actually being consistent with your workouts. Workout clothes are much more comfortable than just wearing a pair of jeans and working out, plus they won't chafe if you get them wet from your sweat. A lot of the reason I have a gym membership is that it provides an incentive to actually get my money's worth by going to the gym (I am rather cheap), thus I'm less likely to not workout. I think we all remember how awful gym time at school was, but a paid for gym is a much better environment, as you can go take a shower after rather than having to be sweaty in your clothes for the rest of the day, or even just working out at home with the opportunity to shower after sweating.
Not a bad idea, my goal is to eventually add a trailer hitch for a cargo carry attachment or even a motorcycle trailer. I've seen a few people with them hauling an extra set of wheels for race day, it can be done but it isn't as clean as just having something holding one wheel. I kinda suspect just having an electric truck with a bed and putting a removable generator is probably the best overall option though (actually saw someone on YouTube make a Tesla powered old Toyota truck that was working on converting a Kubota 3 cylinder to do that).