The prepper in me says the option to burn just any biomass and be independent from electricity, is a must.
Thats why they distribute these ovens even in the third world. Hence: coal and wood. An small electric contact grill with option to form it an oven, I already have.
I also say that a fire from coal adds different flavour to roasted meat, than an electric or gas grill. Which is only natural, since in principle it is a form of intense short-time curing. and nobody can seriously argue that cured and non-cured meat or vegetable taste the same.
Dutch ovens are heavy. Cast iron woks are heavy. But a rocket oven could carry them, despite its small size.
And cheaper than a Weber they are any time.
Any then there is the charm of an open fire (and still safely contained). Indispensable.