The benefit of democracy is that it has somewhat of a self-correcting mechanism build in and it functions without violence. Autocracies don't have that.
You say Democracies have a short track record. While this is true in the grand scheme of things, each individual non-Democracy that came before did as well. Rulers conquered each other's countries, usurped the current leaders etc. quite regularly. I'm not sure I'd count that as stable and longer-lasting.
Autocracies have plenty of self-correction mechanisms. Generally each level is sustained by some kind of grudging consent from the levels above and below.
Right. Usually there is 100% authority in some kind of dictator. You instead have something that is more like an oligarchy. You have different interest groups with varying levels of influence. In some sense democracy works like this too. Every society has stakeholders that need to be bought off or suppressed and there are various equilibria on how that is done.
You say Democracies have a short track record. While this is true in the grand scheme of things, each individual non-Democracy that came before did as well. Rulers conquered each other's countries, usurped the current leaders etc. quite regularly. I'm not sure I'd count that as stable and longer-lasting.