Timeless truth about darkness. All are dead in their trespasses and sin. Eph 2:1 & Col 2:13. Death means separation. Because we have all sinned, Romans 3:23, all are separated from God. Romans 1 presents the truth that deeper and darker depravity is possible. Those who reject God and begin to worship the creation will be “given over” to greater darkness.
The downward spiral continues with the conclusion of chapter 1. This teaches us that sin has unquenchable thirst for more sin and that sin takes us further into darkness as we continue in it. Rebellion against God leads to even greater rebellion against God. The rejection of the clearest light of truth leads to the rejection of all truth so that the mind is so darkened until life makes no sense. That is the place of hopelessness and despair.
God has given all people of all nations the light of His existence in creation. Rejecting the most obvious truth will disintegrate into the rejection of all truth.