Unlike a Torah scroll, a siddur carries no requirement to be handwritten by a trained scribe, it can be typeset and mass printed, which is exactly what made personal daily prayer books widely affordable once printing reached Jewish communities in the fifteenth and sixteenth centuries, after centuries of costly hand copied and sometimes illuminated manuscript versions.
Regional text traditions
A siddur is not one fixed text, printers produce distinct versions following different regional traditions, nusach, Ashkenazi, Sephardi, Mizrahi and Chabad among others, each preserving real differences in wording and order rather than simply different translations of one underlying text. Any publisher may print a siddur, there is no ordination requirement to do so, though traditional publishers typically have the text reviewed by rabbinic authorities for accuracy before release.
Care and disposal
Because a siddur contains the Divine Name in Hebrew, a worn out or damaged copy is treated with the same respect given to a Torah scroll's parchment, not thrown into ordinary rubbish, stored in a synagogue's genizah and eventually buried rather than discarded, even though the object itself was mass produced rather than individually written.