I'm hypersensitive to a lot of things, petrol fumes is one them (yeah, I know), so petrol isn't an option for my stove. Up until recently I used a combination of an alcohol stove (Evernew) and an Optimus Nova+ which I used lamp oil in.
After experimenting with Etapower pots (they have a heat exchanger), I went for an MSR Reactor stove (the pot has a heat exchanger too).

Heat exchangers save fuel, and the MSR is a fuel miser. Yes, it uses gas canisters, but I puncture the canisters after use, so they can be tossed in ordinary garbage. I still carry my tiny titanium alcohol stove because the stand of it doubles as a wood stove, and the evernew stuff takes up almost no room and certainly no weight. This gives me three options when out and about, but my gas stove sees the most use.

I have made a pot cozy for the Reactor-pot, this way I can boil whatever I want, and then let it simmer in the pot cozy, saving even more fuel.

I try to save fuel generally. Not because of the money (which is miniscule, all things considered), but because it allows me to carry less/cook more days.

I solely use 450grms gas canisters (the big butane ones), because they last the longest per overall weight.

Now, why don't I just buy food at stalls? Well, I like to prepare my own. I like to make my own coffee, I like to camp out and do a bit of writing, and I like to be out there with no people.

This is the reason I also row (on the ocean - think sea kayaking, but with a rowing boat) and do trips like that.

I like the camping experience. If I had to buy everything from stalls, I'd simply stop traveling by motor vehicle or go on rowing trips camping. I don't carry all of my stuff on my back, so there's no need to be dependent on food stalls: I can get my coffee and food how I like it, when I like it.

And when I feel like buying food from somewhere I can do that too. Having camping gear doesn't preclude nice hotels, B&Bs, restaurants or anything else. It merely gives me that bit more choice.