system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Why do fast food places sell burgers, but not hot dogs? Burgers and hot dogs always go together outside of fast food places.

Hey thanks for the explanations! Also, to everyone who keeps saying "Sonic sells them" or "this place or that place seeks them", that is not an answer to my question.
gpt
In the simplest terms, hot dogs take longer to cook, and fast food wants to move as much food as it can in as little time as possible.

There are ways around the hot dog cooking problem, historically known as 'systems'. The 'Coney Island System' uses a hot water bath to keep dogs hot and ready to serve. Rhode Islanders will be familiar with the related 'New York System' which involves keeping dogs (more specifically, hot wieners) hot and ready on a low-temperature grille. (There is more to the NYS than this, but this is the part specific to hot dogs.)

Both the above prepare food even if it won't be sold, and any that isn't sold will be wasted. Modern fast food does not tolerate that, not on the scale of the major operators we're familiar with.

A related factor is taste. Americans are just more into hamburgers than hot dogs, in contexts other than tailgaters and cookouts. The potential sales volume doesn't justify the potential waste, especially on a large scale.

Countless smaller operators still do both, but most of the big ones don't. Some do, though.

In the case of McDonald's, the brothers' original barbecue-centred menu was replaced in 1948 with a much more streamlined one focusing only on bestsellers, which did not include hot dogs.