I wonder if age is a factor in these "phases", particularly Phase 2.
I can envision someone who FIREs in their early 40's to me much more susceptible that those FIREing at, say, 55-60.
In your early 40s, very little of your peer age group is FIRE-ing, and IMHO it is more likely to feel the peer pressure of "do something with your life". It is also more likely to get "bored" with leisure things ("do I really want to be doing this for the next 40 years??")
On the other hand, after 55, one may see enough of one's peer group also retiring, and focused on the leisure side, so one is less likely to feel that pressure. Also, one can more readily recognize that the odds are more likely that they have a max of another 15-20 years at their current health and activity level to experience things, so that becomes the priority.