The thing about bit addressability is not completely true. If you can address memory only in pages, you can have quite a large write amplification, depending on the access pattern. A single byte written may count as $PAGESIZE "written data".
A lack of bit addressability means that hammering one bit would burn out a whole word/page, but it doesn't affect how many cycles it takes to reach that burn-out point, unless you've got wear leveling.
In practice, if you burn out any one bit, you need to retire a chunk of the array at least as large as a cache line. And it's not likely that you'll actually be able to directly hammer a single bit, because the endurance is still low enough to require ECC.
