I don't mean this to sound rude, though I know it will, but this is the literal definition of "argument from ignorance."
You don't use more than two burners, so you don't know why a stove needs more than two.
I personally frequently cook with three or all four burners. Further, there are meals where I might use the two small back burners, and meals where I might use the two large front ones.
I guess you could be describing a need for stoves that came with just two burners, for those who couldn't imagine using more. But, seriously, would you have bought a two-burner model if it had been available, knowing that you might have wished for more even one night a year?
There are also down considerations of power (wiring and maximum output) and noise (induction units have fans, which are less noticeable in stovetops), safety (accident risk from cables, tilting, etc) and convenience.
It might work if your everyday usage involves zero to one units. Which is certainly possible, if you don't cook much, but even if you are and you're using other heat sources like a rice cooker, oven, grill, microwave, etc.
Not a terrible idea to have one around when you're limited by your normal capacity, or when you want to simmer a stew at a buffet, or your stovetop breaks or you are redoing your kitchen.
Aor of Indian households when preparing a traditional lunch will have 5-6 items (in the south, particularly in a Brahmin household, you will have one sambhar, one rasam, three vegetable currys, rice, and a fried item usually appalam). This entire meal takes three hours or so to prepare from scratch on my stove (a three burner lpg stove). Two more usable burners will cut this down to about 2 hours
This is not even remotely typical.
> This is not even remotely typical.
Digress!
What is typical?
It is always good to learn about people's lifestyles....
It's hard to make broad generalizations. But having been to all six divisions and having lived in three of them, I feel very confident in saying that a household that cooks three different curries, sambar and rasam for a single meal is very atypical. What GP described sounds closer to a restaurant set course meal and not something a household would cook on a day to day basis.
So, they had 5 burners?
Anyways, my comment was more about the number of dishes. Two curries as in your example is fairly typical. Three curries, a sambar and a rasam like the GP said is definitely not. Chai at lunchtime does sound strange to me but then again, I'm not really familiar with Punjabi culinary preferences.
The practical reason is that people have different sized pots and pans. I don't want to put my small sauce pan on a large burner that will waste the majority of its heating surface. Similarly, I need a large surface to heat a big pan.
The aesthetic is that a lot of cooktops are combination stove/oven and thus have to be big enough for the oven bit. Once you already have that surface area, you might as well fill it up to make it seem more substantial. A stovetop with room for 4/5 burners will look like the manufacturer skimped out if it has only 2 burners.