For most people it's nearly impossible to admit something they just dedicated a large portion of their life too was completely worthless.
(standard disclaimer statement that of course there are exceptions to the trend.)
Well, then don't do your PhD in the US. I did my PhD in the Netherlands, had a reasonable salary and a good work-life balance. I now work as a habilitant in Germany (roughly the equivalent of an assistant professor), it's the same: good salary, good balance.
The primary problem in the Western/Northern European academic environment is getting a permanent position. So, I might end up in industry in the end ;).
In addition, a PhD is highly valued by companies in Germany (where I live now), so your higher starting salary usually makes up for the low income during your PhD.
That said, doing a PhD for financial reasons is usually a bad idea. For me, a much better reason is that you can work on a deep (and interesting) problem for 3-5 years, becoming an expert in a given topic and training your gumption, which will help you to tackle difficult problems later in your life, even in unrelated fields. Compared to research work, most projects that you can do in industry are rather boring in comparison (there are exceptions of course). So, if you do a PhD, do it out of curiosity and not because of the title or the hope to make more money later.
I would be interested to know what the process was to move from the US to France for a PhD.
Finding a grant/supervisor is quite easy for a strong candidate. The critical part is too choose wisely the topic. Research tends to be very specialized and you may end up with a PhD that gives you few marketable skills.
I would be interested to know what the process was to move from the US to the Netherlands for a PhD.
Many European research groups use English as their main language for communication. Also, outside academia many people in Western European countries and Scandinavia are proficient enough in English to communicate with. (Though in my personal experience, English proficiency in Germany is quite bad compared to e.g. The Netherlands or Denmark.)
The country I would be most hesitant about is France, they really don't like speaking English, and most French PhD theses are still written in French. This is really idiotic, all it does is slow down the dissemination of research; some acquaintances who did their PhD in France were looking hard for a non-French external examiner of their PhD, which is the easiest loophole if you want to write the thesis in English.
I believe it's a stereotype and it's certainly not the case in CS research labs. I did my PhD in a French research institution (INRIA). In my group, a majority of the people didn't speak French. And of course, PhD students could write and defend their thesis in English if they wanted to (I don't know if they had to find a non-French external examiner, but it's likely to be the case that some examiners are foreign anyway).
Because English is the lingua franca of most academic fields? If you are publishing in English conference proceedings and journals, isn't it reasonable to write your thesis in English as well?
(Note that English is the default language of theses in many European countries.)