Wrong again ... sorry Robin ... you are clearly a bright chap, but not a markets person.
Firstly you assume central banks declare all that they purchase ... they do not. The days of the Washington Accord where they telegraphed their moves in advance is now a generation ago ... official buyers are nuanced and discrete. Secondly you seem to think retail buyers are the driving force ... this would be like drinking the ocean through a straw. The physical pipelines are tiny in comparison to the global market ... stocks are small and rapidly bought out ... most dealers shelves are empty and they struggle to resupply as capacity for conversion from large bars to coins and small bars is very, very limited. Where we might find accommodation is the ETF sector which certainly has seen an uptick but this is primarily a channel for institutional investors.
But the over-arching reason I believe you are wrong (again) is price action ... retail investors are skittish and after such massive gains they are prompted into profit-taking and getting stopped out easily ... and that is not evident. Dips are brief and bought into aggressively ... sentiment and conviction from those larger players who are concerned about debt are evident. What we are witnessing is gold playing its role as an asset of last resort in a world awash in debt ... we are witnessing a loss in trust and hence bitcoin crashing as gold rallies ... buy the analogue ... sell the digital ... and we are seeing globalisation in full retreat as nations hoard strategic assets as instruments of economic hegemony.