As just one example, a tech employee whose unvested RSUs are sitting at the 2021 highs might be more willing to splash out on all kinds of things -- vacations, restaurants, a nicer fridge, primary or investment residential properties, etc -- than they would if the share price was a lot lower.

Middle America's 401k gets hammered (pushing retirement off x-years) and small set of tech workers can't buy as much? Seems more harmful than good. fwiw, I don't have 401k/and I own a tiny amount of stock.

As rents go up, these rents eat up most of the wages, thereby increasing wages. Increasing wages cause inflation, and it is called "cost-push inflation", as both cost of goods, cost of services include wages.