Nolan focuses on spectacle. He's good at most of it. He's pretty consistent at being good at most of it. However he's not flawless ( weird problems with his audio, doesn't do great directing traditional action scenes, character development is generally paper thin, etc)
The struggle with being known for being the "spectacle" guy is you need to keep topping yourself. If you don't have a gimmick ( TENET was a film built around a gimmick, there's no denying that any longer) then you can only change the venue.
Thus Nolan is moving to "water" He's going to focus on water based spectacles for a while now. Most of The Odyssey, the probable big spectacle sequences will happen on water. IMHO it's less about The Odyssey as much as it's a battle tested story that's a vehicle for a different playground for more spectacle. All star type casting is kind of a workaround to having a thin to mediocre script and minimal character development. In effect, you are asking the audience to accumulate all of Matt Damon's roles in your mind, and let that imprint carry over into a Nolan film as part of the "character development" Just like Denzel Washington in the Equalizer series. He's basically Alonzo from Training Day, Malcolm X and Creasy from Man On Fire rolled into one. It's the same character archetype.
Nolan is good for movie theaters. He creates big tentpole films that get enough people excited enough to drive somewhere, sit through an hour of previews and ads, deal with douche nozzles on their cell phones and bringing their crying babies and pay the money to see his films. I don't think the actors and characters matter as much in Nolan films as long as they are skilled enough to patch over what is usually a poor script.
The practical gap separating Nolan from Michael Bay in the mid to late 90s isn't very big. He's the art house version of Michael Bay. And the slightly underrated The Island was Bay's attempt at being a bit more of an arthouse Nolan version of himself. But, if you had to weigh it out, you can actual understand the dialogue in Bay films, well when there aren't explosions going off and car crashes. So, bizarrely, Bay might actually be a little more fundamentally sound than Nolan.
Where this will get kind of interesting is eventually Nolan will run out of big spectacle themes and gimmicks, and then the only thing left is sex. "Sex" on screen is the last true big "spectacle" that hasn't really been covered right to the edge of the line. I'm not talking about outright porn, I'm talking about sex in a visceral way that generally hasn't been considered game changing on screen. Even Lars Von Trier, with two Nymphomaniac films, couldn't pull it off, and he's a legitimately talented filmmaker in his own right. At that point, I'll sit back and laugh. It will be Nolan, making a film as close to porn as possible, but not porn, where no one can understand the dialogue anyway.