Why Large Segment != Large Block Sizes (necessarily)

Because if a session is going to read a high proportion of the table/index/partition thereof then it ought to be using parallel query, and that bypasses both the buffer cache and the regular read mechanism.

With index-based access this doesn't apply of course, but with index-based access the number of LIO's on the table is not reduced anyway.

How does that sound for succinctness?