Partly both, all nations should be viable and interesting to play. I obviously get why France and Austria each have more events and missions than Hadoti and Ennarea combined, but I still play the latter type more frequently.
My issue with the Ottomans is that it favours one country to the detriment of multiple ones that gets much more heavily skillwalled (Candar, Karaman, Trebizond, Ramazan, Dulkadir, Knights, AQ, Samtskhe, Georgia, Imereti, Albania, Athens, Byzantium, Wallachia, Moldavia, Epirus, Knights, Damot, Hadiya, Ennarea, Alodia, Makuria, Beja, Janjiro, Dongola, Kaffa, Hisn Kayfa, Ardabil, Ardalan, Gilan probably and some others I forgot about) which just isn't anywhere near worth it for making a country whose biggest issue is that it's too powerful to be any fun to play even stronger.