My research experience is not that great (half year during my bachelor final year) and it's more about Europe than US - but from my experience (and have some family members in academia) it's soul sucking because it's "survival of the fittest" race. Race for money, grants, contracts, permanent position. You go from postdoc to postdoc, from country to country, from one university to another, from one grand proposal to another, zero stability, you beg for money all the time. You don't do what's interesting or risky - you do what's hot, safe and brings grant money to the university - because without that you can't survive. My thesis advisor (professor so he already held a holy grail of academia - permanent position) was working on single method (and guess what - it was industry-oriented) for 15 years because it was a gold mine. He was improving it little by little, it wasn't hot, myserious and ground-breaking. Slow, steady progress, doing almost same thing all the time. He didn't acually do research - PhD students did. Instead he was sitting in his office all day writing grand proposals, making callphones and writing papers. You need to write papers, a lot - for the sake of writing papers. You could write one, bigger paper but instead you write 3 slightly different. The more the better. He was one of most successful people on my university because while being 70+ years old he was working from 7am to 8pm, had gold mine method, lots of grands, connections and papers. Tbh in normal industry you have less stress and more freedom. You don't need to fight for your survival all the time. If you are good enough - you will get a job. If you don't like your current company or project - you can change it, you can have work-life balance and stable 9-5 job in one company for many years. You don't need to beg for money and prove your skills all the time. You don't have to teach if you don't like it, you can choose location and company you want to work for - in academia you don't have this kind of luxury. That's why I think academia can be dark and soul sucking.