To use the wheelchair ramp analogy, we don't allow businesses to decide to rip out existing wheelchair ramp installations because they're too costly to maintain.
Perhaps we need more prominent labelling on packaging or in stores when a company adds an allergen to a product that did not previously contain it. This would reduce the potential for surprises. Or right now, to address this problem that many people aren't aware of, much more prominent labelling of sesame to sunset in a few years.
Other methods I've heard proposed by industry is establishing a threshold for sesame to be listed as an ingredient.
https://www.fooddive.com/news/sesame-allergen-american-baker...
Most people with a sesame allergy won't have a negative reaction to traces of sesame. Drawing a distinction between a product that has traces of sesame and one that has sesame as an ingredient would allow for easier compliance.