Well in fact we know (if P! = NP) that for any randomized ALG there's a good deterministic one. So its not going do the kind of game changing class breaking work you're looking for. You know, where random is the only way.

How randomization helps is by making it much easier to design algorithms. E.g. Verifying a solution is cheap, so proving your random choice is in some class of good choices and making an algorithm that turns that into a solution is still an interesting approach and opens up solutions to things we cant yet solve.

Derandomizing as presented apparently means proving for a few random but careful choices you're in the funnel towards the right solution, or (hopefully) can detect otherwise, and a few transformations or reasonably performant steps produce your solution.