My blog is 16 years old. I've rotated through several blogging engines in that time (Bloxsom, YAWT 1.0/2.0, Pelican and finally Eleventy) but they all have one thing in common: they all process blog entries stored as plain text files.
The fact that all my blog entries are stored as plain text files on my computer is, I believe, one of the main reasons my blog has lasted this long. Text files are trivial to back up. Text files don't really crash and rarely get corrupted. Text files are readable and writable on any computer manufactured since the 1980's - hell, the 1960's if I let punch cards into this conversation. When you contrast this simple durability with, for example, a MySQL data store (used by several blogging engines, including one of the most popular ones, WordPress), with all of its attendant version compatibility and data corruption issues, the superiority of plain text becomes undeniable if you're trying to write something that lasts.