The "without form, and void" description in the Hebrew of Gen.1:2 is not accurate. Hebrew tohuw va bohuw points more to the condition of something laid waste.
Even in the KJV, we are shown the earth laid waste at Gen.1:2 with a flood of waters upon all of it, covering the whole earth (i.e., "face of the deep" and "face of the waters". The subject of those "face of the waters" continues all the way to Gen.1:9 when God gathers the waters left upon the earth to make the dry land appear. He didn't create the dry land with that; the earth was already there underneath all those waters.
A summary:
Gen.1:2 - flood waters overspread upon the whole earth (heavens and earth was created back at v.1).
Gen.1:6-7 - a firmament (sky) divides the waters upon the earth. Part of the waters are moved up into the sky, forming today's atmosphere around the earth, and the rest of the waters are left upon the earth still covering it whole.
Gen.1:9 - God gathers the waters overspread upon the earth to one place to make the dry land appear. (Not creation of the ground of earth, but a revealing of the earth already existing underneath those "face of the waters" all the way back in v.2).
In Jeremiah 4:23-28 the tohuw va bohuw ("without form, and void") is used again, but it is about the earth going into a waste state because of a destruction by God's fierce anger. Thus using Scripture to interpret Scripture, the Gen.1:2 tohuw va bohuw event is NOT about a gaseous ether state of nothingness; it's about the earth gone into a waste and ruin state. That is how tohuw is used in the majority of KJV cases, about something once good going into a bad condition.
In Romans 8, Apostle Paul points to that destruction of old, long before Adam. Some like to think the creation went into bondage along with Adam when he and Eve sinned, but there is no evidence of that. Even at the end of Hebrews 12 Paul relates to how God will once again shake not the earth only, but heaven also...
Heb 12:25-27
25 See that ye refuse not Him That speaketh. For if they escaped not who refused Him That spake on earth, much more shall not we escape, if we turn away from Him That speaketh from heaven:
26 Whose voice then shook the earth: but now He hath promised, saying, "Yet once more I shake not the earth only, but also heaven."
27 And this word, "Yet once more", signifieth the removing of those things that are shaken, as of things that are made, that those things which cannot be shaken may remain.
KJV
"Yet once more" is about a future shaking that is coming upon this earth that will be about ending man's works off the earth. That's "things that are made" point to, i.e., man's work done by his hands. The things that won't be shaken are about the things of God's creation, including those in Christ.
Yet the underlying question put forth by that Hebrews Scripture is, just when... was the previous shaking of this earth? When did God previously do that? We know He destroyed man in the time of Noah with a flood, but that won't cover all those events of Jeremiah 4:23-28 where He shook the earth, and all the hills and mountains moved... and there was NO MAN...
Jer 4:23-28
23 I beheld the earth, and, lo, it was without form, and void; and the heavens, and they had no light.
24 I beheld the mountains, and, lo, they trembled, and all the hills moved lightly.
25 I beheld, and, lo, there was no man, and all the birds of the heavens were fled.
26 I beheld, and, lo, the fruitful place was a wilderness, and all the cities thereof were broken down at the presence of the LORD, and by His fierce anger.
27 For thus hath the LORD said, The whole land shall be desolate; yet will I not make a full end.
28 For this shall the earth mourn, and the heavens above be black: because I have spoken it, I have purposed it, and will not repent, neither will I turn back from it.
KJV
That last verse is talking about the sky above the earth being black, which points to dark storm clouds. Because of that event, the sky above would be black, which is about the storms created in the earth's atmosphere for today's... earth age time.
Furthermore, Satan was that "old serpent" in God's Garden that tempted Eve. So Satan was already in the role of adversary against God by that time of Adam and Eve. So when did Satan first rebel against God? because in Ezek.28, Isaiah 14, and Ezek.31 we are shown that God originally created Satan a good cherub perfect in his ways, until ... he rebelled against God in wanting to be God. Satan already being the adversary in the time of Adam and Eve moves the time of his original rebellion back to before... that. So when was that?
That Jer.4 ancient destruction upon the surface of the earth by God's fierce anger suggests that happened at a time way prior to the time of Noah.
Because of this, how old the earth is really doesn't matter. It's simply that Genesis 1 shows this earth could be close to 7 to 10,000 years old, or it could be millions of years old. We have no absolute way of knowing.