What, pray tell, is the difference between microfiche and a photograph of the document, apart from size?

In every place where I've had to resort to microfiche (admittedly mostly in "company libraries" and for industrial reference materials) microfiche was always <47% legible, usually the films were covered with enough dust they could have been stored on an open beach (it felt like sand), the original shots were usually out of focues on alternating sides of adjacent frames so that you had to re-focus the reader twice for each frame, and the projection bulb in the reader was within about 4.2 minutes (or less) of burn-out every time I turned one on. And there was always a scratch through and obliterating the one number you really needed. About 30 minutes at a time was the limit for most users, leading immediately to 3 aspirins, a cup of strong coffee, and a calm dark room for about a half hour to get rid of the headache.

(I know it was a rhetorical question, but I'm pretending you really meant to ask.)

Some early microfilm wasn't much better, although the later 16mm and 35mm "filmstrips" usually had much better legibility, possibly because the winding into "rolls" kept the film flatter (or more at least more uniformly curled).

References on CDs, in magazine-loading readers were a vast improvement - usually; although even with them you could only search what someone had indexed when the disks were made.

Digital full text, preferably with tags (SGML - if anyone remembers it?), was a great idea, but there's still ¹little material archived that way where it's accessible to most of the world.

¹ As a percenatge of what needs to be archived.

John