Totally understand your viewpoint, with your level of experience it's borderline offensive to ask you to jump through similar hoops as a recent graduate. Arguments of standardization/filtering and homogeneity of candidates aside, let's be a little contrarian.
You've been doing a job for x years. There's been some personal development and it's been challenging (maybe you're now managing 10 developers and are having to write proposals, for example) but ultimately you've not had to prove yourself in the way you do in an interview in over a decade. What's to say you haven't allowed other aspects of your skillset that you've acquired over the years? If you're reviewing 20 peoples' code per week, when would you have had time to code out your algorithms? Using your own example, it's not at all unusual for senior doctors to lose their skills at suturing or putting in IVs. That's not to say that they've not acquired other valuable skills but there's also something to be said about keeping your fundamentals sharp.
Now maybe I've been drinking the kool-aid, but my understanding is that at your Googs and FBs they have open remits and expect their staff to be dynamic and quick to learn. One of the most valuable skills in that case is sharp fundamentals.
Losing that familiarity with the nitty gritty is a perfectly human thing, I saw it happen with professors being "outsmarted" by undergrads while at uni and early into my professional dev career I am already feeling certain aspects of my skill base deteriorating, I can only imagine what it'll be like in a couple of decades.
With all that, it's not hard to imagine why your big 5 do have such rigorous hiring loops, especially when they're already oversubscribed...