Freeza really did mess up power levels, I mean look at this
>Piccolo was 4k at his death
>He only trained with King Kai for ONE WEEK (remember he got there just as Goku was traveling to space) so let's give him the benefit of the doubt and say maybe he's up at 7k now.
>He fuses with Nail, someone at 42k.
>SOMEHOW REACHES A POWER LEVEL OF ONE MILLION

and Vegeta was even worse
>18k at Earth
>Gets a Zenkai and goes up to around 22k
>Beaten up by Zarbon, gets a Zenkai but is still weaker than 40k (Recoome)
>Beaten up by Recoome, gets a Zenkai, is suddenly strong enough to fight 500K first form Freeza

There's a reason Toriyama dropped power levels quickly after this arc.