As everything in life, to gain something, you need to sacrifice something else. With RDBMS you get mutability; but to go 10x or 100x faster/larger you need to make hard decisions.

HDFS, S3 and other systems have immutability in-built. Immutability is not bad per-se, as it give (some) assurance that data has not been tampered with, and although it could be implemented, the system cost could be significant.

Stricking the right balance is the challenge