It would be really easy for the industry to do a half measure on this one. All of the big companies could get together and agree to accept a certificate that you get by passing a few of those white board algorithms rounds. It's just such a ridiculous waste of effort for everyone involved to test these things over and over again in an NxM interviwers x jobs loop. When you go for an on site interview you should be evaluated on the work you've done and what you bring to the company. Throw in some system design for senior people if you must, since that at least is a bit more specific to the tech stack you will actually be using.