The Daleks on the old show were far more powerful then have been recently, they were the first of the Doctor's enemy races to gain the power of time travel. And they were fighting wars on several fronts. They even scared the Times Lords enough to send the Doctor back to destroy them. The major idffernce now is that we can see thousands of Daleks onscreen now.
I disagree even. Even at the height of their power they never could directly oppose the Time Lords. Their time traveling technologies were also pretty limited since they could only send a few Daleks at a time and they could not travel through both time and space (only time).
In "Dalek", the Doctor is pretty clear that a single Dalek could destroy an entire city and could wipe out whole armies. They also seemed to have mastered both time travel and even basic Time Lord technologies .
And yet the Time Lords forsaw a future where the Daleks were the dominant race in the universe and ordered the Doctor to take them out which is what started the Time War in the first place.