I can't believe the writers found an excuse to have the Slowpoke and Magikarp songs that Pokemon put on YT over the last few years as insert songs in an episode.
In any case
Magikarp segment: I like that it was essentially Magikarp Jump the minisode, with elements from said game appearing during the training montage (like the jump counter which also appeared in Stadium). Speaking of, it's a shame it was never stated whether that Boldore was a random one (to reflect Boldore Push) or Ash's. I'm going with the former as Ash's older pokemon for the most part don't exist in this series and Boldore does appear as a training thing in Magikarp Jump. On another note, Magikarps can get abs? That's an image I wasn't expecting to see. I do like that the ShinyKarp guy was flexing, saying that he hasn't used his full power in the run up to the finals which in itself is a classic trope that shonens like to use, and then Go counterflexes by saying "Yeah I put a physical restraint on my (Level 100) Magikarp because why not?". I'm not surprised that Go lost on a technicality.
Slowking segment: This was some trippy af bs. First of all Go galaxy brains himself by trying to capture the Slowking after the pokedex explains about its intelligence, and speaking of said pokedex, there was no mention of the King's Rock in relation to Slowpoke's evolution into Slowking even though it was established back in the original series (EP260). Of course I will say I like that the episode continues the trend of featuring pokemon that haven't been seen in ages, in this case the last Slowking to appear was Conway's in DP over 550 episodes ago. In any case, the exchanging of Slowking's crown among Ash and Go and the dialogue during which was real WTF territory only for the trippy situation to be quelled by Go's (Level 100) Magikarp to land on top of Slowking.
In any case, I did enjoy the Magikarp segment over the Slowking one.