Confusing. Under what circumstances would I use a presentation programme (browser, chrome) for an input task (writing), which I do on my laptop, in "Writer"?
Regardless, Ctrl-Z only became commonly bound to an "undo" function in the late 1990s or so, IIRC.
Before then, "Undo" was often non-existent. In some programmes, it still is, let alone hundreds of levels deep.