Europe is an appealingly nebulous concept for writers, a place that is fabulously varied, steeped in history, and yet as much myth as a geographical reality. What constitutes the continent, after all, which countries are included, and where are its borders?

There isn’t really a definitive line in the east – somewhere in Russia, we might shrug, the Bosphorus that divides Istanbul? But whatever Europe is, it’s a location that millions dream of reaching. Some of these people turn up in Ben Judah’s This Is Europe, a powerful piece of reportage that develops many of the themes and techniques that he displayed in his groundbreaking earlier work, This Is London.

The book is divided into 23 chapters that each take the name of a different town or city, and essentially focus on the plight of one person therein. So in Budapest we find Ibrahim, a Syrian refugee who yearns to act, to attain financial success, to be a celebrity.

All of which he achieves, after a fashion, by becoming a porn star in his low-budget, self-directed videos that have apparently taken the Arab world by storm. His is an extraordinary story, recounted with such urgency and immediacy that the reader is projected headlong into a world about which most of us know next to nothing.

You emerge dazed and a little confused, unsure whether Ibrahim is to be celebrated for his indefatigability and resourcefulness or damned for his base instincts and crass materialism. Judah doesn’t waste time or space on such opinions. His interest is in showing us the reality of the lives of others, mostly those in extreme or marginalised positions. They may be doing something out of the ordinary, or utterly mundane such as delivering Amazon packages – but all of them are united by a restless need to get on, to fit in, to make Europe work for them.

Judah has uncovered some amazing tales and compelling characters, but what they say about Europe as a geographical, social or even mythical entity is not clear. For one thing, such is the intense, stylised nature of Judah’s prose, with its short, breathless sentences and insistent repetitions, that pretty much everyone he features is rendered in the same stoically desperate voice.

Whether it’s a young Turkish Erasmus student pining for her Austrian boyfriend, a disgruntled Romanian long-distance lorry driver, a Latvian teenager drawn into online sex work, an Ivorian migrant who goes through hell to get to France, or a Galician boat mechanic involved in illegal fishing in the Antarctic, their individuality is slightly lost in a relentless pounding mass.

Is this Europe? Yes, to an extent, it’s the Europe that we usually prefer not to dwell on and never to experience. Judah is to be commended for his deep journalistic curiosity and unflinching gaze, yet there is an unexpected irony here. For all the energy and dynamism that his subjects demonstrate, their often sad and soulless lives in a sense dovetail with more pessimistic and conservative visions of this old continent, such as Douglas Murray’s The Strange Death of Europe.

While Judah would doubtless be alarmed by the comparison, it’s notable that a number of those he documents, in particular migrants themselves, complain about the migrants they encounter – whom they characterise as immoral or criminal.

Given the predicaments the subjects inhabit, which are mostly perilous or exploitative, this is probably no great surprise. Still, you can’t help wonder whether this human churn, this vast cheap labour source and the global instability that drives it, is sustainable.

Postcard Europe, with its Alpine villages, Riviera high life and proud national cuisines, is not under existential threat. However, it’s unquestionably a bigger and baggier organism than that which traditionalists and nostalgists like to recall. The map is still being drawn in the east, where a war rages that threatens the security of the whole region.

In these uncertain times, the fortitude and adaptability shown by many of the people in these pages is cause for optimism. Often, though, they crave stability and legality, the solid foundations that Europe represents to them, while frequently finding themselves forced to live in precarious and illegal ways.

If that is a longstanding feature of migration, it’s one that Europe needs to address if it’s not to fall prey to the xenophobia and bigotry that has in the past exploded so destructively across these lands.

• This Is Europe: The Way We Live Now by Ben Judah is published by Picador (£22). To support the Guardian and Observer order your copy at guardianbookshop.com. Delivery charges may apply