It was never good when you compare to internet search.

On the internet I can search for "pictures of the eiffel tower". If I try the same on my own computer I expect to find photos from the time I took the family to paris... Yet I don't.

And yet Gnome and KDE have no troubles doing just that if you activate the corresponding plug-ins for the respective search engines (Tracker and Baloo). How you access them is a matter of taste, but both integrate into your runner dialog or launch menu, if you wish.