The fact that elephants once extended to the Middle East was news to me. I imagined a herd of elephants peacefully bathing themselves in the Euphrates, perhaps near pre-Sumerian cities, and made myself sad

the extiction of megafauna around the world is an ongoing process that humans by competition and outright hunting have accelerated inmensenly. In fact I believe that animals such as the Tiger and Lion once extended even farther than from we know, but by the time the first humans started registering them (like the Greeks in the case of the lion) they were in the way of extinction already.
I was about to propose elephants as work animals in China and other places, but they aren't that useful, while they're strong and smart, they take a LONG time to breed, and they're somewhat fragile, so it's not the best idea. They're used in India even today but never in mass scale projects.
I'll look for some more sources.