Also, where I live if I'm too lazy to cook or get off my ass my delivery options are limited to those types of places. Basically. Is this just a matter of those being the most popular options?
I think I've hit at least half a dozen previous iterations of this question, but I've only hit one real albeit brief answer and a pointer to the answer. TL;DR: /u/ quince23 said, "If the OP is specifically interested in the recent rise of cheap ethnic food delivery, Jennifer 8. Lee's fabulously readable The Fortune Cookie Chronicles devotes a chapter or two to the history of its resurgence in mid-century NYC."
A search finds these previous questions, but looking at them, few seem to be addressing delivery specifically and don't seem to address the reason for popularity. I mention them in case you want citations of books, or perhaps more bits on the history.
More relevant info is here for pizza:
In terms of New York Times coverage, which is probably a leading rather than lagging indicator for national food trends, pizza "first surpassed hamburger in Times coverage in 1976. The two bounced around in close competition for the remainder of the 1970's, but in 1982 they diverged, and pizza never looked back." It's worth mentioning that, while the hot tog only occasionally competed with the hamburger, the taco is now in second place (behind pizza) in terms of all casual foods mentioned in the Grey Lady. So pizza became was popularized in the 1950's, common by the 1960's, everywhere by the 1970's, and seemingly America's favorite (casual) food by the 1980's.
A word called 'Agribusiness' began to sprout up during 1948 - in this sense, it can be used to mean "Reduce skill/resources required to produce something, reduce nutritional value, but increase profit."
This is where pizza and Chinese food come into play. Before the 1950's, American people liked to rely on convenience foods to take to work (i.e the iconic American ham and cheese sandwich, potato chips, grapes and a soda lunch) and with the affluence of the 1950's, this convenience became a marketing strategy. This part doesn't need much explaining - You have a lady over (I'm assuming you're a straight male, I hope that's not too presumptuous of me) and you both have had a long day, so you order pizza and watch a movie on the couch - because you value convenience, and this convenience is marketed. It's not considered lazy, you both just really want some greasy food and easy entertainment.
It's also a fair thing to add that a common, incorrect argument is that Italian and Chinese immigrants came over (or even more fanciful, soldiers came back from WW2 and spread what they found in Italy) and made their food the same way they did in these countries, and we were all in wonder and awe and copied them - which is incorrect. We, as capitalists, simply capitalized off of a very easy-to-make food. I dare you to go to China, and find authentic battered, fried chicken balls with a cheese filling - or go to Italy and find a deep-dish bacon-covered pizza sold by a LOCAL business.
This subject is covered in a book called The No-Nonsense guide to World Food by Wayne Roberts, but ServeSafe also delves a bit into it as well - Name your food something "authentic" but just make it out of something cheap, and profit.
I hope this helps!