Most people don't understand the plumbing in their house, let alone the market.
When money comes in to the market, stocks rise, When money goes out of the market, stocks decline. If you sealed market inflows and outflows - individual stocks may go up and down , but the overall market would be constant. Its truly that simple.
Ever wonder why they raised the 401K/IRA minimum distribution age in 2019 and made it so people over 50 could put their entire paycheck in their 401K? Hint - it wasn't because the IRS is benevolent - it was because market inflows were turning negative. Look at a stock chart for late 2018.
So in 2019 more money rolled into the market, and the printing of 2020 juiced it. Names like TSLA, META, NVDA and LRCX were in the headlines so they got most of the juice. Same thing for .com. 401K's really got rolling in the 90's. The internet was going to change the world. I already posted about CSCO and Lucent. Look at INTC - still in business, still a household name, still in almost every PC - but they have since never come close to their 2000 peak. Adjusted for inflation there likely 1/3 (guess, I haven't done the math).
Additionally, stock buy backs are just another form of inflow. Not only do they lesson the number of shares, but they bring new money into the market - from profits or debt or whatever. Buy-backs help the whole market, not just the stocks buying back.
So maybe its different this time. Or maybe all the boomers still sitting on a million in AMZN will grow a brain cell and buy the 10UST @ 4.2%. If they don't, Janet will convince them, she needs the bid.