The 70k to 80k year mark does seem to be significant. You might find this article below interesting. The cognitive basis for these changes seems to date from around then, but it took time for that to translate into broad societal changes in physical culture.
https://neurosciencenews.com/language-imagination-evolution-...
The near simultaneous development of agriculture world wide 10k years ago is still a conundrum. I think it is a bit easier to accept as a coincidence if you view it as the result of a few tens of thousands of years of fairly rapid development, compared to the previous hundreds of thousands of years.
I think it’s likely to be a combination of factors. Parallel a social and technical developments on the one hand and maybe climate change induced crisis. It doesn’t have to be one single factor.
Humans went through a massive cultural and technological transition some 40,000 years ago into what’s called behavioural modernity. This was a transition into complex symbolic and abstract thinking which generated developments including music, tattooing and body painting, decorative artefacts, advanced stone blades, compound technological artefacts composed of multiple parts or features, more sophisticated clothing, etc.
By multiple features I mean things like a bone needle with an eye hole. Such things didn’t exist previously. We did have basic single piece clothing similar to blankets or ponchos with some simple weaving, but everything prior to 40k to 50k years ago was dramatically simpler than later periods.
These developments enabled the colonisation of previously uninhabitable climatic regions, allowing modern humans to finally spread out of Africa and conquer the planet.