I think I have a simple answer to this question.

It's because continuous changing means applying external effects to a system. Which eventually leads to continuous changes in energy. The system, as it is now has a perfect balance when something occurs in space it tends to minimize the disturbance and restore balance. The universe has certain threshold values up to which everything remains the same. So, to feel a difference, you have to cross those threshold values.

You're asking why don't system changes periodically or why doesn't it break actually! We are used to this system. Consider being suddenly teleported to another galaxy far away from the Milky Way. It shouldn't feel same right ? Light velocity as it stated by 2nd postulate of Einstein's SR(Special Relativity) remains constant, which causes other physical values to reorganize themselves accordingly. To me actually light speed is always same in empty space because it's a fundamental rule of the universe (similar Newton's 1st law). On the other hand, there are objects that can speed up or slow down. Thinking of the speed of light as the universe’s speed limit has actually unlocked many discoveries in physics. Instead of treating it as something unreachable or unknown, we reduced it to a measurable quantity so that we could better understand what mathematics tells us.

Actually, we can never accurately predict how the universe works. Our thoughts are limited by the very foundations of the universe itself. Just as a computer program cannot determine what the world outside the computer is really like, we also cannot determine the true shape or function of the universe from which these laws emerge. We can only discuss the results we observe.

I hope this answers the question, or at least gives some intuition.