Induction requires your cookware to sit flat against the surface or it won’t heat up (and the range will shut off after a certain time). With natural gas the flames rise through convection and wrap around the contours of the pan. This means many traditional pieces of cookware with round bottoms simply will not work on induction but work fine on natural gas.
Induction also requires the cookware to be ferromagnetic. This rules out a lot of traditional cookware materials such as clay, copper, brass, and stone. Many of these traditional materials are also accompanied by traditional shapes (round bottoms, gently sloped sides) that take advantage of the convection properties of open flame cooking.
Many recipes rely on these traditional vessels for optimal cooking performance. Woks, for example, work much better with a round bottom so liquids can pool in the middle, letting you use less oil for stir frying but still allowing ingredients to spend time in the pooled oil.
The temperature profile of a round-bottom wok over gas flame is also superior to a flat-bottom wok on induction: the traditional wok has a bright hot spot at the bottom (where all the oil is pooling) in addition to heat up all around the sloped sides, for rapidly reducing liquids that come out of foods and cooking sauces (soy sauce, shaoxing wine) with an arc-splash technique. The flat-bottom wok on induction has a uniformly hot surface on the bottom but the sides remain cool, causing all liquids in contact with the sides to run down to the bottom and begin boiling, just like when you try to stir-fry in a frying pan.
Candy-making is another cooking process that benefits greatly from the convection of natural gas combustion, since molten sugar will crystallize around the sides of a pan if they are not hot enough. Traditional candy-making is done in thin-walled, tin-lined copper pans. These pans don't work at all on induction (no ferromagnetic materials) but even if placed on a ferrous plate they would not perform well due to lack of heating of the sides.