Doubling your options doesn't double your decision time, it barely adds to it
In 1952, psychologist William Edmund Hick measured how long people took to respond as the number of choices increased, and found reaction time rises with the logarithm of the number of options, not proportionally. Going from 2 choices to 4 adds a small, fixed amount of time; going from 500 to 1,000 adds about that same small amount again. It's one reason well-organized menus with fewer top-level choices feel faster to use than ones that dump every option in front of you at once.