Until this fight shows a new power-up for Luffy and Hybrid Loki against Imu, it’s just going to be a friendly spar. I’ve seen comments bringing up Kaido, but people forget that Base Luffy fought Hybrid Kaido for quite a while. It implies that Oda doesn't know how to develop fights—many are worse than mere fan service, as the battle only gets serious once Luffy and his allies are in their strongest forms. It’s the same with Zoro; until he puts on his bandana, the fight is nothing more than trading blows between friends.