Is it though? I mean it's sure helpful if that's what you want to do, but it's not like that was impossible before. Given that relatively few people make use of it (relative to the population) it seems to be a small win, easing the bureaucratic process for a small number of citizens (that, I suppose, in Western Europe are generally wealthier than the average, and wouldn't exactly have to jump through hoops before).
Also in the past people moved abroad for work. Now it's easier, from a bureaucratic and economic perspective. Doesn't mean everyone WANTS to move: most people are perfectly happy living in their hometown, or at least same country, as long as you can make a living there[1]. But this should not surprise anyone, it's not that most refugees would leave their countries if they could find a job and security in their homeland .
[1] btw, I have no stats but the feeling is that most internal migration in Europe is from the poorest countries and/or social classes to the richest countries. Which, again, makes a lot of sense...
[citation needed]
There are vast numbers of cross-border workers and internal (to the EU) migrants. I don't have numbers, but I really think that statement is misleading.
But the possibility of moving permanently (or to study at the university) to another country without needing a visa, well, that's a game changer. Not to mention the agreements between European countries (e.g. If you move, there's no need to change your driving license)