The apparent record holder for most prolific author is Charles Hamilton
Wonderful stuff!
The penny-a-line market endures - I know folk who knock out endless stuff, supposedly non-fiction, for online clickbait mills.
Do they dream of a by-line one day? Or is that now out-of-reach? The conflict is played played out daily on sites, such as The Guardian, where freely-donated comments under-the-line are
sometimes a lot more thoughtful and intelligent than the articles that provoked them.
Back in Regency & Victorian times, the public appetite for three-volume novels seemed endless. A flood of authors was recruited to fulfil the need. Untangling their identities, at this remove, is problematic but it can safely be presumed that many were female, as were the majority of novel-readers. Payment rates were miserable and the works were bought outright with no hope of royalties for a success!
Before that, there was Grubb Street . . .
While many people daydream about becoming authors, I am always reminded of Sam Johnson's stern warning about writing and money!
There was similar mad productivity in the early days of the gramophone. Some artists would dash between studios and record their current numbers under new names - for a few shillings a time. Some of them stayed productive for decades but they needed to! Others would dream about the fame and fortune they would have, if they could only make a record!