Speaking to AFP ahead of his headline appearance at next month's Hong Kong International Literary Festival, the author argues that people are sometimes "so aware of the bad things tourism brings, we forget the good things".
"In many cases, in Rajasthan in India or Bali, the advent of tourists has woken people up to native customs and traditions that might have been falling away, and moved them to take care of their heritage and even expand it," he says.
And while he has noticed a huge increase in visitors to Japan, his home for three decades, the 62-year-old doesn't think people should stay away.
In Kyoto, where the serenity of the city's ancient shrines and temples draws less-than-peaceful daily crowds, he says it is still possible for travellers to walk their own path.
"There are times in November, peak season, when I'm walking down the central street in Kyoto and you can barely move for all the visitors. But one street over it's just as deserted and evocative as it ever was," he explains.
"Kyoto has been around for 1,300 years and I think it's wise about knowing how to take in the whole world without being completely changed, or spoiled," he adds.
Iyer has written on topics from globalisation and jet-lag to spirituality and rootedness. His work reflects on his journeys to more than 80 countries, as well as literature and his long friendship with the Dalai Lama.
Born in Britain to Indian parents, Iyer grew up between California, where his family moved when he was small, and boarding school in the UK.
He began his career as a writer on international affairs for Time magazine, but at 29 swapped fast-paced Manhattan for Kyoto, planning to spend a year in a Buddhist temple.
While there, he met a Japanese woman called Hiroko and fell in love. She left her husband and the couple moved into a small suburban flat in Nara, an hour from Kyoto, known for its giant bronze Buddha and sacred deer park.
As well as seeking pleasure and new experiences, tourists should ask themselves what they are going to give to a place, "not just materially, but in the form of human contact or friendship", or attention to problems faced by people there, Iyer says.
The "urgent" issue of climate change also means travellers must be able to justify long trips, he adds.
Last year a record 31.2 million tourists visited Japan, according to government figures -- a massive surge from 2.8 million in 1989, when Iyer had just moved there.
Behind the stats is a worldwide travel boom fuelled by cheaper flights, eased visa restrictions, and a growing middle class in China and increasingly India. Successful Japanese tourism campaigns and international events like the Rugby World Cup have also contributed to the influx.
Even though more people than ever are on the move, this doesn't mean they have more in common, according to Iyer.
"The world isn't small, and in some ways, the distances and differences between us are greater than ever before, partly because of the illusion of shared culture," he says.
In Iran, he visited a packed restaurant called Kansas Fried Chicken -- "the closest they could get to KFC" -- where Steve Jobs's autobiography was on display. However, he points out, its popularity "doesn’t make Iran politically or economically any closer" to the US.
Similarly, Japan may have embraced baseball, but it has turned the American sport into "something deeply Japanese". And in India, "there's a bombardment of stuff from everywhere else, and yet unmistakably at every second, you're in India, for better or worse."
In Hong Kong, Iyer is due to give two talks: on his new books "Autumn Light" and "A Beginner's Guide to Japan", and about the search for stillness in the hectic modern world.
"For me, travel is a way of gathering lots of experiences and prompts and emotions, and stillness is how I make sense of them," he says.
Iyer spends several months each year with his elderly mother in California, but says when he's in Japan, unlike anywhere else, "every day lasts for about a thousand hours" as he avoids using technology as much as possible, instead taking breaks to read on the terrace or play ping-pong at his local health club.
Given the angst over mass tourism, and the need for stillness, should everyone slow down and explore closer to home? Perhaps, Iyer says.
"There's a famous rock garden in Kyoto with 15 stones... people always pay homage to that place, but just around the corner is a little stone wash basin with one Japanese character on each of its four sides. They say: 'what you have is all you need.'
Sometimes, you have everything you need right there, he says -- "you don't have to go across the world to find it."
* Pico Iyer is speaking at the Hong Kong International Literary Festival which runs November 1-10 (https://www.festival.org.hk/)