I'm not an expert, but my views of faculty was that many spend much less than one would think on research. According to 1 study [0] "Research – 'and the external funding and recognition it brings' – makes up just 17 percent of the work week and 27 percent of weekend work,"

Based on personal experience, I gave up the idea of a Phd when I saw how much time the professors spent begging for grants. And I've learned the most within the first 6 months of a new position. (This is also why jobs that offer a lot of variety are nice)

[0] https://www.insidehighered.com/news/2014/04/09/research-show...