Your basic error is considering anything about this as logical, it is a mess, mainly politics but also policies that have been changed, altered over the years.
Also you are showing EB1, now that is a tiny percentage of work visas. And I am sure your total process was a lot longer than 8 days.
Generally work based immigration visas take longer than Immediate Family based visas. At the other end you could find really long times, look at F4 and EB3 India.
As far as actual processing is concerned of course an I 130 does not take a year, less than an hour, I have seen various times mentioned. So most of the time factor is the case sitting somewhere.
You could also look up DCF times which tend to be a few months start to finish and I have seen some that have been very quick.
They seem to introduce different programmes without thinking through what will happen. The various Humanitarian Programmes, and my favourite is the U Visa. I remember seeing that launch for victims of crime, 10,000 a year and wondering how quickly that would go wrong. Many victims of crimes are also criminals. And of course everybody and his dog applied, so there is, last time I saw a 30 year backlog and growing.