Why is streaky bacon excluded from a traditional English breakfast?

Streaky bacon is excluded from a traditional English breakfast because it is cut from the pork belly and is composed primarily of fat, causing it to shrink and crisp during cooking rather than remain a substantial meat component. In the English breakfast, bacon refers to British back bacon, cut from the loin, which provides a balanced ratio of lean meat to fat and serves as a principal protein on the plate. Streaky bacon is widely used in commercial settings because it is cheaper, cooks faster, and is more forgiving of overcooking, but these qualities reflect operational convenience rather than culinary equivalence. Its cooking behaviour and structural role differ from that of back bacon, and increasing its quantity cannot replace the absence of lean meat. While common in other breakfast traditions and contemporary menus, streaky bacon does not fulfil the functional role of bacon in a traditional English breakfast and is therefore not regarded as an equivalent substitute.