For me I loved 4e, and was incredibly disheartened when the edition died. I had begun playing Pathfinder at a friend's request (running it since it was similar enough to 3.5 and the group was newish to the ruleset) and naturally it was 3.5 but different, so what bothered me about 3.5 still bothered me in PF. 5e came out and I found it utterly lacking in the depth necessary to maintain my interest.
I actually went through something like half a year or more where I was profoundly angry / frustrated at my rulesets because each of them were failing me in a specific way that I couldn't reconcile without doing a TONNE of work. I tried to do that work, creating hybrid systems and gestalting PF and 4e (was fun but oy character creation took forever), but nothing stuck.
So since I was still playing with a group who were adamantly Pathfinder fans I continued there. It didn't take too long however for the Pathfinder 3pp to fill the small gap in what I wasn't getting from PF. Once I had Path of War, Sphere's of Power and Ultimate Psionics, my Pathfinder world now had every little style of fun I could possibly hope for, so now I can't fathom changing to another system. I'm hooked for good.