It "just" means ages of ages, eons of eons when the word combines ages and ages. Maybe at the end of those God will actually make it all cease to exist for them. Men of earth often say eons represent millions of years, into the billions, which can be held to them by God.
Ages of Ages is translated from Owlam. The Greeks didn't really have word to translate owlam and as such used the phrase ages of ages. However, the word owlam meant, until an unknown time. It was use of a distant time in either the future or the past. Literally it meant beyond the horizon. What is beyond the horizon cannot be seen. This was the concept of owlam, it didn't mean eternity. Here are few uses of owlam
KJV Exodus 21:6 Then his master shall bring him unto the judges; he shall also bring him to the door, or unto the door post; and his master shall bore his ear through with an aul; and he shall serve him
for ever. (Exo 21:6 KJV)
Obviously both of these men will die so the servant will not serve the master for eternity.
20 And thou shalt command the children of Israel, that they bring thee pure oil olive beaten for the light, to cause the lamp to burn always. In the tabernacle of the congregation without the vail, which is before the testimony, Aaron and his sons shall order it from evening to morning before the LORD: it shall be a statute
for ever unto their generations on the behalf of the children of Israel. (Exo 27:21 KJV)
This ordinance in the English translation is said to be for ever, yet both the Arronic priesthood and the Mosaic Law ended. Jesus and Paul both tell us that the Law came to an end. If the Law ended then the ordinance is not an ordinance for eternity.
43 And they shall be upon Aaron, and upon his sons, when they come in unto the tabernacle of the congregation, or when they come near unto the altar to minister in the holy place; that they bear not iniquity, and die: it shall be a statute
for ever unto him and his seed after him. (Exo 28:43 KJV)
Here is another ordinance that in English is said to be forever, yet the Law and the Arronic prieshood ended. There is ordinance after ordinance that in English is said to be forever which is translated from owlam and yet Jesus and Paul tell us that both the Arronic priesthood and the Mosaic Law ended. So, we have choice, we can look to the translators or Jesus and Paul. My money is on Jesus and Paul. From their words owlam doesn't mean forever, I'm siding with them.