From what I can tell this is actually one of the sort of mysteries of Ottoman rule. If you know the basics of all the administrative details then I won't repeat how they may have been different from elsewhere, but M.E. Yapp's "Making of the Modern Near East, 1792-1923" points out that despite descriptions of internal dissent, problems of imperial authority, ethnic and religious conflict, foreign interference, the loss of Egypt, the "sick man of Europe" that despite that the Ottomans suffered through incredible losses, yet held out in Medina until January 1919, and that "Under no worse a strain Russia collapsed through internal revolution; no such event overtook the Ottomans and those who argue that the fall of the empire was predestined through its internal dissensions must ask why the empire held on through the war."

It's a question he doesn't answer and I'm unfamiliar with any works that delve into it.

edit: I'd love to hear from anyone else who knows more about Ottoman or Safavid rule though, my area of study is almost exclusively on Arab territories, and with a significant gap from about 1500-1820.