We need a democratic centralized party structure
What is your sample size for making that conclusion, and how many variables are you correcting for?
I'm going to leave aside the last 50 years of history of DemCent parties, because there are no lasting victories to point to in that period.
Only hardcore disciplined communism can defeat capitalism.
There is nothing that says that hardcore disciplined communism means "you have to report up the chain of command just like in a monarchist/capitalist army" or "you shouldn't be able to converse with your fellow cadres from other divisions without approval or oversight of upper management". In fact, being adapted to the local conditions, and being able to organically build power starting from a household or neighborhood level is extremely important for being a disciplined communist.
If you don't believe in decentralization, why are you posting on an instance of Lemmy, instead of assembling a clandestine organization to seize the structure of Reddit, or to make an armed coup that takes control of Reddit and puts it in the People's hands?