It is not like there were not good moments in Wano. Wano was good, Onigashima was bad.
So, to be specific, Onigashima had:
1) Scabbards facing Kaido, even though they knew they cant win
2) Robin fight
3) Focus on Zoro (his arc)
4) Sanji and raid suite issue resolved
5) Momo's decision to man up
6) X Drake and SWORD plot
7) Apoo being Apoo
8) Hawkins getting what he deserved
9) Kidd and Law awakening
10) Sky splitting
11) Kanjuro not turning into a good guy
12) Kaido beheading Orochi (just crushing his confidence was satisfying)
13) Chopper making vaccine for oni virus
14) Kaido still going strong (if he has awakening that will be cherry on the cake)
15) Myself, for taking time to think about these good moments and still not liking the overall Onigashima raid. If I listed 15 good points, I can list 150 bad things about Onigashima. It just has been that bad.