I’ve noticed some people with seemingly fulfilling hobbies stop doing them after quitting their job as well. It’s entirely possible all those hobbies are valuable precisely as something powerful to latch onto and disconnect from the day job, and seem pointless the day after quitting. Seems like you had a strong sense of identity outside of your job already before quitting. Building that could be a lot of hard work for other people (and it sometimes comes as a surprise that it even needs to be built).