The Crusades were nothing more than a series of massacres for a land grab and the Crusaders failed the minute they encountered armies who could actually fight back. Knight Wank is fascinating because it’s almost entirely based on fictional portrayals where the Europeans in tin cans won all the time against evil monsters and savages.
I was always convinced that crusades “failed” about as much as American wars - the developments in some third country are irrelevant (and also subject to easy propaganda, since only one side can fud people), where the real money & power comes from is from campaigning, money collection, arms industry, etc. In that was a vast success. People that actually went crusading were just necessary with a secondary (low) possibility of extra payout.