Mitch Case explains Romans 8:22 in his longish article, “What Does It Mean That All of Creation Groans?” Not just people suffer under the heavy load of human sin but nature too. The apostle Paul uses personification to illustrate that all life eagerly anticipates the glorification of God’s elect.
The heavens do declare the glory of God, but the wicked deeds of his image-bearers declare something as well: the corruption of sin and the shadow of death that pervade this creation. Given the condition of creation, Paul told the Romans that we’re not the only ones longing for what is to come. “For the creation waits with eager longing for the revealing of the sons of God” (Rom 8:19). Indeed, “the whole creation has been groaning together in the pains of childbirth until now” (8:22).