The safe withdrawal rate was calculated by looking at all 30-year periods since 1900 or so and seeing if any of those 30-year periods fail (“fail” = “run out of money before end of period”). The period beginning in 1929 is the worst case.
Therefore, you can withdraw more than 4% if, and only if, you believe that a sequence of 30 years as bad as that one can never happen again.
That said, there have been all sorts of variations on the standard SWR study done over the years. There are “reset” ones, where you reset your withdrawal each year, or every few years, as your portfolio goes up or down. There are SWR studies done for 100/0, 50/50, 20/80 portfolios. Etc.