Charcoal gives you more usable heat than any camping stove, costs almost nothing, and needs no gas fitting. For anything that wants a wide hot surface rather than a single ring, it is genuinely better than a burner: flatbreads cooked directly on a grate, a pan of onions actually browning rather than sweating, several things at once.
What it is bad at is control and timing. A charcoal fire takes twenty to thirty minutes to be ready, is at full heat for a while whether you want that or not, then fades. That suits food you cook in one pass and suits nothing that needs a twenty-minute simmer.
The Food Standards Agency’s test for whether it is ready:
make sure the coals are hot enough before you start cooking. They should be glowing red with a grey, powdery surface.
Never take it inside, and never take it into an awning, a porch or a van. Charcoal produces carbon monoxide the whole time it is lit, including while it is cooling and looks finished, and the people it kills in the UK are usually the ones who brought a cooling barbecue in for warmth. This is not a small risk carefully managed. It is the single most dangerous thing on this page: carbon monoxide.
A lidded kettle type is worth the extra bulk over a flat tray if you have the space, because the lid is what lets you hold a moderate heat instead of only a fierce one.