People who think the Gods are like half a billion years old are merely thinking stupidly or just are deeply misinformed with crap they read online. But pay not attention as said people are already deeply deluded with grand delusions, and this is only part of these.
Half a billion linear earth years, is a time frame people cannot even comprehend. If Satan and the Gods were there for like the huge amounts of time people assume and write, we would have conquered galaxies as they have, not struggle with just maintaining a single planet in a half asses manner or falling to hooknoses.
Time can also be quite trivial. A germ can exist for millions of years and do nothing absolutely, but be a germ. Time is relative and in the case of the Gods, their thousands of years time accounts to knowledge and power that would normally take millions or tens of millions to achieve conventionally by evolutionary standards. In this case, yes, one might as well say, they are extremely far more evolved in existential years than linear earth years.
The travel of the Gods to this place was relatively short. Even in the Egyptian eras like 10000 or more years earlier, they weren't here all the time. They came and went. This is iterated in the Egyptian Pyramid texts. Cultivation of a species should be done patiently, and the Gods have been really patient with us.
On the other hand the Greys and other aliens are accelerating growth as one does that to a vegetable by adding fertilizer eternally. This is because to them we are merely a plantation, and they want to borg us out as quickly as possible in their terms. The promise of quick "evolution" towards becoming borgs is part of this.
Given that some specific human beings can cause world change by times such as 30 linear and normal earth years, 500,000 is just an insane amount of time.
Asmodeus is anywhere from 6000 to 10,000 years old. Age however does not always directly decide ranking. Another Demon from the Demon section that existed as a demigod in the last 10000 years is Balaam. Balaam's legacy survived even as a Demon who even in the Torah is commemorated for launching a curse that killed tens of thousands of Jews at the time. This even they have hid in cryptic words, but this is what is said between the lines.