Given that the maximum file size of combination of direct, single indirection, double
indirection, and triple indirection in an inode-based filesystem is approximately the same as a filesystem solely using triple indirection, why not simply use only triple indirection to locate all file blocks?

-Did you not read the answer to Question 42?! Spatial locality! For smaller files, it keeps the amount of disk accesses (which are expensive, given that there is a mechanical component otherwise known as the disk head) low to read any block in the file. The amount of disk accesses grows with the levels of indirection we have – a direct block only requires one operation to read, a single indirection requires 2
operations (one for the indirect block, one of the block it's pointing to), and so on