TBF you've got to be slightly obsessed to see the metrication in A-series: most people will interact with A3 and A4 papers which are respectively 420x297mm and 297x210mm, if you go up you end up with A0's 1189x841mm which doesn't look very metric either. You've got to realise that it's 1 sqm in a sqrt(2) ratio to see the metrication (the aspect ratio being chosen so it stays constant when you halve the page through its larger edge).

The B series actually looks "more metric" at first glance: B0 is 1414x1000mm.