It ends its research in a few seconds. Can this be even thorough? Chatgpt‘s Deep Research does its job for five minutes or more.
Likely they throttle and do a lot of waiting for nothing during those five minutes. Can help with stability and traffic smoothing (using "free" inference during times the API and website usage drops a bit), but I think it mostly gives the product some faux credibility - "research must be great quality if it took this long!"
They will cut it down by just removing some artificial delays in few months to great fanfare.
Similarly, their inference GPUs have some capacity. Spreading out the traffic helps keep high utilization.
But lastly, I think there is just a marketing and psychological aspect. Even if they can have the results in one minute, delaying it to two-five minutes won't impact user retention much, but will make people think they are getting a great value.