The needs of a startup are quite different than (and often conflicting or opposite to) the needs of a stable, large company. So if you have learned "what good l

The needs of a startup are quite different than (and often conflicting or opposite to) the needs of a stable, large company. So if you have learned "what good looks like" elsewhere and have no first-hand experience in a high-growth environment, then you as a founder may be prone to decisions that are a poor fit in the context of a startup, which by definition is a high-growth. Launching an "ordinary" (i.e. non-high-growth) new business in an established niche will have much more overlap with previous work experience at some corporation than trying to get product-market fit for a startup.