That's surely the case for everybody? I can't imagine bothering to go to work for less money than I'm making in the evenings/weekends - why not do the 'side hustle' full time instead, or use the time for something new, or family, or whatever.

I do not know, but I am not changing strategy.

This year, just like I did for the past 10, I invested all my paycheck savings into VTI/VXUS despite suffering 6 figures unrealized losses from them. I plan on doing the same next year, and for as long as I am employed/have disposable income. Every spare dollar I find, outside of my emergency fund, gets immediately invested.

Yes, because I like buying things for a lower price than a higher price.

Not the GP, but I would say yes. I am 51, and I have seen a few economic boom and bust cycles.

I think you can almost boil it down to: if you think civilization will collapse, then do not buy stocks. If you think it will still be around, buy stocks. Things might look bad over the next few years, but I think things will get better after a while.