I think when it comes to repeatable content, the best kind of Splatoon gameplay tends to be matches with downtime edited out and comments on what the player was thinking edited in.
If you look at other games that are very content-friendly, they tend to produce content where the gameplay footage is accompanied by the creator talking and engaging with their audience. If you take a competitive Splat gameplay vod and slap it into a youtube video, it doesn't bring that level of engagement with it. Splat is simply too fast paced and the player is generally going to be focused on the game (and communicating with their teammates if it's a scrim or whatever). A combination of editing out downtime + comments edited in mitigates that, and I think that a good player outputting this kind of content consistently has a ton of room to grow a channel. This is even more true for solo gameplay where the creator is speaking to the audience about this stuff already.
I've seen players create this kind of content, just not consistently. It takes a lot of work and probably requires an editor to do it long-term. Still though, if I think about the kind of Pokemon, Magic the Gathering, etc. content I typically watch when I want to sit down and eat breakfast while watching content about a game I like, the reasons I choose to keep going back and watching that kind of daily content are mostly present in a type of Splat video I describe here. I don't think they're found in the "talking about a new development in the Splat news cycle with gameplay in the background" or "we did this goofy thing and THIS is what happened" style videos that I see very often from Splatoon content creators. It's fine if those things sometimes get incorporated into repeatable content but those are one-off video ideas and can't carry repeatable content on their own, IMO.