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human
[Dragonball Z] Why is it that Frieza can't detect power levels?

He has incredibly powerful telekinetic abilities, yet this seems to be a major lapse in his training; especially getting to the scene where Goku is gathering energy for his Spirit Bomb... Did he simply become too dependent on Scouter technology to complete a task that seems to come quite easily to the various heroes in the series? I can somewhat understand the lesser villains lacking this ability, but in Frieza's case I am left wondering why...
gpt
Frieza had never needed to sense power levels, because everyone was either weaker than him or a close relative and ally. And we can tell it's not a common ability since the Planet Trade Organization all used scouters instead, from the lowest Saiyan grunt all the way up to the Icers themselves. The only other race we know of who had the ability to sense ki (without learning the ability from Earthlings) were the Yardrats, who required the ability in order to use instant transmission (by focusing on a ki signature and then teleporting to it). 

Of course, there's also the ability to sense good or bad in a power signature, as demonstrated by Piccolo right before he met Raditz. But it's not clear whether this ability is endemic to all Namekians or specific to Piccolo himself. The only clue would be Nail's recognition of the Ginyu Force as "evil," but then, Nail was the most powerful Namekian alive at the time. EDIT: It's possible that only the "warrior-type" Namekians could do this, but who knows?

tl;dr: Ki sense is a rare ability, that's why they have scouters. Besides, why would Frieza need to sense power levels? He's a monstrous power with a billion underlings.