Choosing the right blocksize for Oracle Database tablespaces with lobs
LOBs are managed in chunks (groups of blocks), not blocks, so there's not really anything to gain with this. Oracle assumes that an 8k block size is &quot;universally good&quot; for everything. By increasing the block size, you could potentially wind up wasting storage space that can't be efficiently allocated for smaller files because the chunk size is too large.
See here for a running discussion: https://asktom.oracle.com/pls/apex/asktom.search?tag=oracle-block-size
Final analysis:

That said, worrying about block size is like fiddling while Rome burns -
many (most?) apps have low hanging fruit which will give a better ROI on your time than tuning the block size.
8k is still best block size to be using.