What's especially ridiculous about imitating Google's hiring practices is that the value in Google's search/ad business was largely built by people hired there before these interviews become the norm. They hired through social networks, like, hey, you and X who works here had the same PhD advisor.
The ridiculousness isn't that Google has changed their hiring process to reflect their current state, it's that other companies are copying what Google does now with the hope that it will allow them to replicate the success that Google had 20 years ago.
If your premise is "We look a lot like Google circa 2015, and I really like what they've done since then, how did they do it?" then it might make sense to replicate their hiring.
But if you want to achieve what Google achieved between 1998 (founding) and 2004 (IPO) then asking what they do now (or have done over the last 10 years) isn't particularly relevant.
