An Egyption slave pulling a huge block wasn't any more creative than most people today. There happend to be one guy who figured out how to move enough huge blocks to build a Pyramid

Not that it has anything to do with anything, but recent archaelogical research has shown that the actual workers on the pyramids, were a) not slaves, b) well treated - e.g. better fed than average, good housing, had health care available, etc. c) proud of their work. Perhaps there were only a few architects, but architects aren't the ones who find the solutions to the many practical problems of implementing the archtitect's design and there's evidence that many of those solutions were provided by the teams of workers.

As to the "this younger generation isn't as good as we were" meme - I think it's safe to say it's always been around and has both truth and falsehood in it. One difficulty in comparing ancient inventiveness to modern inventiveness is the shoulder-standing thing. If our ancestors hadn't invented, language, writing, math, etc. we'd have a difficult time doing all the things that are supposedly smarter than the things our ancestors did. OTOH, any civilization that pays people to lie to them (advertizing) can't be the smartest bear in the forest.