As I recall, ... the Olympians, Egyptian, and other ancient old world diefic entities were basically all a result of humanities first discovery of the Well, but since they found a much more potent Well because it was, assumingly, filling up for untold eons, compared to what Cole found in Greece around five thousand years later. Plus world human population was, for simplicity, say five million when the ancients found it. Compared to around two billion in 1928. [] According to one graph I found. [] https://ourworldindata.org/world-population-growth
Because it not only cured Cole, and mutated Richter (Recluse) but the reopening of Pandora's Box also gave rise to Nemesis, the Dark Watcher, gave Team Vambrace that final spark of ingenuity for their power armor to work right. The Well was not only power, but also like the Mind Infinity Stone fueling ingenuity and progress. Granted Statesman and Recluse got the Lion's Shares for this new heroic age. But when they opened the box almost everyone also got a piece. It's just not everyone can access their share through whatever means.