That doesn’t change what OP said. It’s still keeping up mystery for mystery sake. But if you want to nitpick, fine. Helena being “in or out” in the first few episodes was mystery for mystery sake too. The “mystery” is largely being lied too/kept in the dark, not being given a satisfying riddle.
If the mystery only exists because you deny the audience information the characters know, it’s not a mystery. It’s just slow lying.
It’s really quite simple and doesn’t take a novel to understand.
When the audience is given all the same information as the characters and are trying to solve it at the same time as the characters, it’s a plot driven mystery.
When characters already know the answer and the audience is kept in the dark(especially with editing/cuts) until the last episode of the season, it’s mystery for mystery sake. If the plot can’t exist without intentionally keeping facts from the audience, it’s mystery for mystery.
There’s no harm in being Oceans 11. But don’t pretend this is something it’s not.
And just gotta say “man wants to rescue wife” is the most reductionist take on the plot and shows why you find what little that was there as satisfying. The “plot” is about a cult like company that does an insane medical procedure on its employees, and part of the plot is that they did it to a couple and reunited them. At least, that’s what we’re hunted at. It’s also about all we’re actually given.