The problem is you are demanding a full fight when Oda has never done that in the past. Oden vs Kaido was an absolute serious and important fight, but Kaido never used hybrid, never even used haki.
Oda could have drawn something more for Harald vs Loki? Sure, but as he could have with Kaido vs Oden.
I am not demanding a full fight .
Your missing my point which is the fights were to differnt be it how there done in story aspect to compare them power scale wise.
End of the day no matter how fight went Harald had to died where with rocks Oda show you can hit people out of DR .
With rocks Oda want to show and confirm you can use CoC to block stuff .
With Harald Oda did not care about that when he have fodder damaging him and loki and DF was most important aspect which bring harald back to his sense after attacking him .
To me DR and abyss mark are differnt and way how fight were done where differnt to direct power scale them .
Oda could show long harald fight and he would not have character say harald using CoC to block stuff because he could have done that in chapters we see harald attacking and getting attack .
To me loki is very impressive but i not going to use that fight to put him over Roger or Garp or WB , Luffy , Shanks etc etc .