It's centralised because the central government sets the direction and priorities but in reality provinces and local governments have a lot of autonomy and the central government sometimes struggles to keep them in check.
The main issue, IMHO, is that because there are no checks and balances (no independent judiciary, etc) local chiefs are all powerful and can do whatever they want (and line their pockets) as long as they don't get on Beijing's radar. That's a reason they don't 'like' demonstrations and unrest... And that may be a contributing factor in trying to hide the initial Covid outbreak, for instance: they didn't want negative info to escalate all the way to Beijing.
RE the last point, I read somewhere that concealing 'bad' data led to provinces overreporting their total fertility rates (low birth rates have been an issue in China for awhile). It was recently discovered and adjusted accordingly that TFRs were in some regions even lower than suspected.
China has a "hybrid system" --- internally mostly communist, externally strictly capitalist.
This can lead to increased efficiency versus strict western style cut throat capitalism where everyone competes against everyone --- both internally and externally.
But the problem here is that this leaves politicians with full control without any real checks and balances. And politicians can and will screw up almost anything.
The main issue, IMHO, is that because there are no checks and balances (no independent judiciary, etc) local chiefs are all powerful and can do whatever they want (and line their pockets) as long as they don't get on Beijing's radar. That's a reason they don't 'like' demonstrations and unrest... And that may be a contributing factor in trying to hide the initial Covid outbreak, for instance: they didn't want negative info to escalate all the way to Beijing.