Growing global awareness and adoption - There is a growing awareness of Bitcoin and people are seeing the rel life effect of holding and not holding bitcoin. They prefer the former.
Halving - People don't want to be on the "wrong" side of history during and after the event. They don't want any bitcoiner to say"I told you so" if they miss it.
It's a flex- If you are a Gen Z or millennial and don't have some bitcoins. You are almost looked at as old school. We know that is the last thing they want to be called.
The downside, however, is if such a substantial accumulation of BTC is undertaken by institutional investors who have the potential to create a massive barrier or even initiate a Bitcoin dump when the market turns bullish. As usual, price manipulation in an asset can indeed occur, and Bitcoin is not exempt from that possibility.
On the rest of the points you've made, I concur.