First of all, those majors in and of themselves do confer applicable skills. Physics is a quantitative major, in which you learn to do some complex math that can be useful in a variety of careers. You also learn how to problem-solve - how to break down a problem into smaller parts, put together a plan to fix it, and then proceed. That’s putting aside the actual physics, which is pretty useful in many careers.
Philosophy majors learn to think critically, to quickly read and synthesize information, extract themes and motifs, and write well. I am currently procrastinating on a work project that requires ALL of those skills. History teaches you the same thing, as well as how to apply specific issues to general concepts.
Everything we do has art in it - think about multimillion-dollar video games and movies, but also think about advertisements, social marketing/public health posters and campaigns, medical illustrations. Think about the extensions to industrial design or web design.
You have thought of two isolated cases. I have some stories, too, of philosophy, physics, art, and history majors who are gainfully employed in jobs that pay them a middle-class salary.
I don’t know anything about Italy’s statistics, but in the United States, majors in those areas have pretty good post-college prospects. The unemployment rate for recent college graduates who were history and philosophy majors is a bit high - in the 8.5-10% range. However, that’s about the same rate as it is for economics majors (8-10%), lower than computer and information sciences (12-15%), and frankly not that much higher than computer science (7.5-8.5% - that’s within the margin of error, indicating that they’re not significantly different from each other). And things even out when you get more than 5 years out of college - at that point the unemployment rates are functionally the same. And the important takeaway, also, is that the vast majority of people who had these majors ARE employed.
What that means is that a brand new humanities graduate may have a little harder time right out of college finding a job. My guess is because these humanities majors maybe had a harder time figuring out exactly what they wanted to do or could do (engineering and CS majors don’t need a lot of imagination to figure out jobs; history and philosophy majors need a little more). But once they figured out what they wanted to do and could do with their degrees, they were fine. These data are also taken from the depth of the economic recession - from the years 2009 to 2012 - so the rates are also probably a bit high for that reason as well.
If you figure out career steps for you early and develop the kinds of skills that employers want - including internships and part-time jobs in school that help you get experience - you have much better chances of finding gainful employment right away.