[JdeBP]

> Which radically changes huge fundamental assumptions in how legacy file systems were created 30-40 years ago.

Actually, it doesn't. It makes the ones that you haven't heard of interesting again. Consider the BSD 4.4 LFS, for example. The disc is written to as a circular log, with all writes going to the head of the log, which gradually works its way across the whole disc, and a cleanup mechanism emptying the tail of the log. That is global wear levelling in the file system ... in a design from 1990.

This is what you miss when you adopt the mindset that mis-uses the word "legacy" like that.