I think there’s also a variety factor, heirlooms are usually very unique and fun-looking. But yes I think taste is generally good too. I’m growing heirloom Zucchini and Tomatoes this year. The tomato flavor certainly isn’t bad, about on par with other good garden tomatoes. The zucchini on the other hand is out of this world good, and retains the flavor even when the fruits are large, unusual for most other Zuccs. (Variety is Costata Romanesco)

It depends on what you're looking for. You'll struggle to grow something as sweet as store bought sweetcorn but you can easily grow corn with deeper and richer flavor at home. Just make sure to select a variety meant for direct human consumption and not animal feed or ethanol (some are for human consumption but only once processed).

US industrialized food is almost universally bland and tasteless compared to home grown because they're picked too early and bred for aesthetics and transport - it's an issue every immigrant I know struggles with. On top of that, there are dozens if not hundreds of different varieties that haven't been commercialized for every fruit or vegetable in the grocery store so there's a whole world of flavors and textures that most people haven't experienced.

Currently have painted mountain, glass gem and then regular sweet corn. The painted mountain colors are really neat and it is okay to eat, but a firmer and not as sweet (obviously) as the sweet corn. The glass gem corn is not ready yet, but I hear it is good for popcorn so I will try that.

Corn is a hot season grass: it likes growing in large fields with lots of other corn plans near it. Most home gardens are not large enough to grow good corn (you can grow it, but the corn will not do as well - this can still be good enough.) With sweet corn time from field table is critical to good flavor, so people do grow it in their garden anyway, but it would be better to live next door to a large corn farm that you get it from.

I think they taste better than the grocery store varieties but usually it is more difficult growing them, and they have a lower yield than industrial varieties.

There are also general quirks with growing them. Experience lends me to suggest that heirlooms are more immediately sensitive to the environment that convention varieties. Buying from baker creek who are out in the Midwest, Seeds are going to have a different response in the growing in the SE Atlantic region, that response seems more pronounced although I have no idea of how to quantify it.

Ultimately I think it is worth it, it is fun, and it taps into more of the holistic aspects of gardening. For example, learning how to make quesadillas because your heirloom corn gets infected with corn smut, so instead of an infection you have a product.

That kind of frame-shift i think goes into the nostalgia of Doing It How We Used To.

Most people grow sweet corn in their gardens, so they won't be growing these.

There are heirloom sweet corn varieties, but they have to be cooked in minutes/hours from harvesting to remain sweet.

As far as the starchy corn, you won't get a lot of flavor difference.

One huge benefit is that you can keep your own seed to grow next year.

Hybrid seeds usually do not come true to type if kept.

Commercial varieties also often have some kind of IP restriction which makes it illegal to grow from seed you kept.

To my knowledge, zwieback is made from wheat, not corn. /s

Heirloom corn is not necessarily better or tastier. The natives planted different kinds and they each had different resistance to different issues, i.e. drought, soil, elevation. They were diversifying their crops in case something wiped out one of them they had other options.