I think one would find that most likely there is no footing support under this stacked block pier.
I am guessing here, but looking at the picture and not knowing what part of the Country it is, I am seeing that their is no vapor barrier on the ground,
No insulation in the joist space, and the carrying beam is most likely made up of two members with a ledger on both sides with notched floor joist.
That would tell me this block pier is not carrying a tremendous amount of load.
I believe, from looking at the picture that the soil type appears to be of a high relative moisture content which is evident on the bottom block course and the wicking affect in appearance.
It would or could be conceivable that over the years, the clayish dirt settled and the bottom block shifted downward on one end about 30 degrees and the upper tiered blocks slide foward due to the incline.
When the obviouse sagging in the floor, someone went underneath and either jacked it up enough to pack dirt under the block and used what I am seeing as a brick to wedge it up.
So the original block went back to it’s original position, but was still too much pressure at the time to slide the upper ones back where they belong.
Hey, if anything, sounds good dosen’t it? ha. ha.