I can't be certain, but the sample spans different Countries and includes incomes from 0 to a lot, and age, from 0 to a lot.

How do the people you know who have incomes of 0 afford a week holiday?

Let's say that you are on social benefits. Let's say that this gives you 7 euros a day of budget (for most of Europe it's 2 or 3 times that or more). What prevents you from flying/hitch hiking somewhere (you can easily find Ryanair 3 to 10 euros promotion flights), and couch-surfing there? Bonus points: pick a place where life is less expensive than where you live, for actually saving money while traveling.

I kinda agree with you for Western Europe and if you have a really good social network. But that's not the whole Europe.

Let's take the big problem-country in their chart (Romania). Unemployment/social benefits = 100€/month (and you only receive that in the first year after you got unemployed, after that is less); also, you can be required to do social work if you want to keep the benefits (so no vacation for you!)

Minimum salary = 250€/month.

Median salary = around 250€/month (46% of employees are paid at minimum salary and some take less than the minimum as they are not fully employed).

Average salary = 600€/month (because around 10% of employees are in IT)

Average pension = 230€/month

"Normal" cost of living for a person is usually more than 200€/month.

If you're on a minimum salary you probably don't have any savings and you don't know many people outside the country. And you need to know someone quite well so you can couch-surf at their house. Also, people over 50 don't usually know English and the nearby countries speak completely different languages. Usually older people visit their (Western Europe) relatives with all the expenses paid by their relatives, so you can't say it's a real vacation that you can afford.

I don’t this is the type of vacation the article was talking about.

Which makes it a relatively silly measure.

Why do people use shelter when they could just sleep outside? It's much less expensive, you know.

You cannot just sleep outside in general by law in most of the EU. Loitering is a thing. Not to mention weather is often not exactly accommodating, so you would need gear to do that, and while not especially expensive, it is not free either, nor that comfortable.

Quite a few people do take to tent hikes or biking trips which are cheap - excluding time and effort.

Trust funds?

If everyone he knows with 0 income has a trust fund, then he definitely lives in a bubble.

Unfortunately not much of a defense against bubbles. It depends more on how you are choosing the sample rather than how representative it is on 2 dimensions.

I personally know people over a wide range of wealth and income brackets across several continents, including unemployed; but I don't know anyone who is involuntarily poor, because none of my hobbies or social circles would bring me into contact with a person who was struggling to get by.