I'd say it depends on how much you have saved. For most of my accumulation phase I was pretty much 100% invested in equities. I never made a ton of money and figured I needed all the help I could get. If the market went and stayed sour, wouldn't make much difference ,because if I was really conservative I couldn't save enough to matter anyway. Now here I am at 58 just deciding when I should ER. I can go now if I want. Just waiting to see what happens in the election.
If you made good money through your life and have a ton saved, I guess why risk it? Me, I keep 3 years expenses in cash, bonds, and the rest I still have in equities. That gives me the time to recover from a down market and still enjoy the hopefully good returns.