Traditionally in Mexico and much of the South Americas, tortillas were made out of corn flour, it wasn't until European colonialists introduced wheat to their lands that wheat flour tortillas became a thing, yet still it wasn't common amongst its population as due to wheat crops needing more attention being more sensitive to the climate conditions, it was quite expensive and more commonly dined on by the rich and elites. Corn/maize was always easy to grow, and thus cheaper, more common, was largely used by the common folk to make their tortillas.
In Indian culture it seems like wheat roti/paratha/breads were always the standard. Even though wheat seems more native to Asia, wasn't it still expensive to cultivate, assuming similar climates to what was in Mexico at the time? Indian breads are also made from lentil flours and rice flour, how widespread were these?
I'm not sure how to draw the comparison between these two situations you've described, but I'm going to try.
Of course, corn/maize has always been integral to Central and South America, especially Mexico as you rightly pointed out.
However, India doesn't make all its breads with wheat. Heck, even lentils and rice flour fall short.India, fortunately or unfortunately suffers (or one could say suffered) from an interesting diversity of grains. Rice is one of its oldest cereal, a sort of national standard, also one of the oldest in the world. And if we're going back 5000 years before present, and until the present, wheat then is not the only crop - there are multiple millets! Expensive is a subjective term to use in this case, yes, wheat has been slightly more expensive option than another, more widespread and strong variety of crops : millet.Millets are used in a variety of flatbreads, porridges, snacks, juices, fodder - long list of uses really. Foxtail millet, sorghum, pearl millets, finger millets etc.
Millets continue to be an integral part of India's grain ecosystem, although millet production is unfortunately reducing drastically thanks to a classist divide between millets and other 'richer' crops such as wheat and rice. Most of India's arid, dry, rain-shadow climate is conducive to millet and always has been. Millets aren't as expensive as wheat (in most cases at least, unless you go to a rare, high-class fine dine where organic millets are used to carve up a specific dish).This is now ensuring a situation where Indians might not be able to grow all the grains to match their consumption, a problem that can be avoided if millets come back in vogue. It's a pretty sorry, complex situation.
Millets are considered to be a poor person's crop/grain, wheat and rice are considered higher, richer. Hence, wheat has in a sense has whitewashed a lot of recipes, often substitute millets as a 'wealthier' alternative. You could maybe research on millet-based breads and preparations across India, and the history of millet in general in order to understand the sort of local divide between wheat, millet, rice and other crops and get a better overview on the agricultural situation specific to India.
Wheat production also requires a more specific nurturing, timing and rainfall as opposed to millets which are stubborn, more versatile and can weather climate fluctuations.
PS. I'm absolutely fascinated by Mexico's food history and it's a long, old wish to visit there and explore. Thank you!