https://codesandbox.io/p/sandbox/compassionate-bas-lncllp

In the Dev Tool, I found the output is like

1
2

(...wait for 5 secs)

3
4

(...wait for 5 secs)

5
6

It always prints out two numbers seamlessly, though there should be 5 secs interval between them.

I wonder why it is that?

Thanks in advance!