Agreed, the salary difference is brutal (>3x more in industry after MSc, at least in ML…). My PhD experience was similar in terms of isolation. However, I think this does not necessarily have to be this way, it’s just how most academics unfortunately work :-/ advice would be to try to find groups which are more collaborative

I disagree mostly. One should do a PhD if research is what one wants to do right now/for the next few years. The PhD is a unique opportunity to do focused, very deep research at the boundaries of human knowledge. You will most likely not be able to do that at any point later in your career (maybe still somewhat as a post doc, but certainly not as a professor, because then you are a science manager, and also not in industry). Also, the feeling of inventing the future when you make a discovery for the first time is just amazing.

Also, a PhD provides you with unique training to tackle unstructured problems, and having a PhD is often prerequisite to research positions in industry

However, I agree with the statement that one should not do a PhD if salary/prestige is what one wants. You have to be 150% self motivated in a PhD, otherwise it’s a recipe for misery.