World market affairs are important for U.S. market action.
All nothing burgers if you're investing for the next 1-50 years.
Ok, for sake of internet chat, I disagree on two fronts though agree with your overall picture - viewing 50 years. Reality, we didn't know what was going to happen with the global markets. The past is easy to
predict. The U.S. great depression destroyed lives. We didn't know what to expect from COVID. Some thought drinking bleach would cure the issue (Yes, I know - Trump was jesting about the idea... humor folks), others claimed it was the biblical apocolypse. Easy to view from present. The black plague destroyed lives just as well.
Investments are modified as one moves closer to retirement. "Getting scared" is one perspective. Moving retirement $ to "safer harbors" - is another.
Covid caused a stir where many re-allocated their retirement money to other areas. Myself included. Throwing
hypothetical numbers, end of 2019, I had $550k in TSP (Federal + gov % type of IRA) I follow FedSmith for my TSP info. At the start of covid, I had roughly 8 years until forced/mandatory retirement from my field of work, I felt my TSP needed to dock in a safe(r) harbor - G fund.
Others rode it out and - along your line of thought made back their sudden slam losses and continue to ride the market up. September(?) of 2020, I moved $ back into C & S funds and I am good with protecting my retirement from the sudden dump and the
then fog of war [market] activity that ensued. Knowing now? Boy - I would have bought back in even earlier 2020! Haha! Though I do not have the luxury of seeing the future.
In the end - it was a tricky time. Am I worse off knowing what I know now? I may have lost/gained a bit though I was much more secure with my retirement.
In a nutshell, it depends on how close a person is to retirement, IMO.
This is one example of COVID and its, then, unknown affect and what we know now. There are potential events that will trigger me to protect my assets and #1 my retirement $.