You’re mixing up two different questions. "What the market will bear" is a monopoly pricing story.

Food is messy because it's a commodity with a whole lot of substitution-- consumers have a high elasticity as a result.

We are talking about elasticity's prediction for the share producers and consumers each pay when there is a cost structure or tax change. Incidence theory is well validated and fits observed evidence remarkably well, including in 2019 studies of the effects of the 2018 trade war.