Imagine tech stacks are lottery balls. And they ask for 6 specific ones. What are the odds that you've picked the right balls? Unless we are talking about quantum humans that can learn all the things at the same time.
Staying informed, daily, on trends and reading the latest material helps the individual to adjust to meet the changing industry.
Study Computer Science, pick up a few languages, familiarize yourself with various technologies, read white papers and journals, and connect with experienced professionals in the industry. You needn't be fully prepared for all of the requirements, you need only be cognizant of the evolution of the industry and quick to study advancements in your field (as with just about any industry).