This is sad because humans are much much slower than computers and even 1 whole second is nothing to us. At least I am quite willing for Google to take a second or more to give me more thorough results. A query that takes 900 milliseconds is better than the same one taking 150 milliseconds but returning poorer results. The additional 750 milliseconds are virtually unnoticeable in human time and a small sacrifice to make for excellent search coverage.
The only place where every millisecond may count is the case of automated queries running into the thousands and millions. I'm not aware Google even allows something like that and it's a corner case anyway. Human typed search is the majority use case.
Presumably if Google spend 150ms of processing time typically, they don't want to spend 900ms (I'm ignoring transit times, etc.) on one query as they could get 6x as many ad impressions for that processing cost.
They don't even need to do better than the competition, only well enough to stop customers leaving despite having to do 4-5 searches.
When milliseconds count that's important.