Seemingly overbuilt basement wall - load bearing?
This gives all the impression that is was designed and installed to support the basement wall that the &quot;arrow&quot; of the diagonal bracing points to. The vertical post against that wall is what was put there to support that wall.
The bottom of that post is most certainly held up against the wall securely by the bottom plate in that wall which is likely pinned to the concrete floor.
The top of post is held against that wall by having that large horizontal beam bear against the opposite basement wall.
The diagonal braces are keeping the center of the vertical post from bowing in. The studding fitted above and below the diagonals is placed there to keep the long diagonals straight so that they do not bend under compressive load.
You should carefully evaluate what is going on on the outside of the basement wall where that vertical post is located. There may be excessive ground pressure against that wall due to any number of reasons that can only be guessed at. In the evaluation also check the wall itself to see of there is evidence of cracked blocks, cracked mortar joints or overall inward buckling of the wall.
It is even possible, though not likely, that this wall support was placed there based upon past concerns that may not be obvious today.