I don't really follow the misunderstandings here, but on the off chance this re-level-sets the thread: you don't continuously inject new "entropy" (ie: rekey) a random bit generator out of concern that the underlying primitive is "leaking" (if it leaks, you fix the leak). Rather, you do so for post-compromise security, because there is basically no reason not to have some measure of post-compromise security such that if the state of your DRBG is compromised (by some systems vulnerability, not by cryptanalysis), in some relatively short interval security will be "restored" by rekeying.

I think that's pretty much it, the whole reason sophisticated CSPRNGs have entropy pools and stuff.