Jesus has the power of life - life eternal. He IS 'the Life'! (John 14:6) He gives life to the dead. As the second Adam from heaven, he is "a quickening [life-giving] spirit" (1 Corinthians 15:45). But he has power OVER death, and death is subject to him, due to become the last enemy to be destroyed - by the triumphant, risen Christ (vs. 26).
Of necessity there yet still has to be death because there is still sin. And "the wages of sin is death" (Romans 6:23) "but the gift of God is eternal life through Jesus Christ our Lord." A few verses previously: "Moreover the law entered, that the offence might abound. But where sin abounded, grace did much more abound: That as sin hath reigned unto death, even so might grace reign through righteousness unto eternal life by Jesus Christ our Lord" (5:20-21).
Continually, the Bible contrasts Satan's power of death with Christ's gift of life. Satan has that power due to being a lying murderer from the beginning (John 8:44); he is a usurper. Yet for as long as humans sin, they must die, receiving death as their 'wage' for the works of sin they have built up. They must reap what they have sown. However, the good news of the gospel is that Christ enables deliverance from the satanic death-hold over them because Christ has "the keys of death and Hades". He also has the power to cast Satan and his hordes into the eternally burning lake of sulphuric fire, which will be exercised at the last trump.
A point of note is that Christians know that death has lost its sting, for them, because they have already started that life eternal in Christ, which is the first resurrection. Christ was the first-fruits of that, and they are the first harvest. This is detailed in 1 Corinthians chapter 15. Verses 55 to 57 make these significant points:
"O death, where is thy sting? O grave, where is thy victory? The sting
of death is sin; and the strength of sin is the law. But thanks be to
God, which giveth us the victory through our Lord Jesus Christ."
Someone may have a lot of power (including the power of deception) and may be keeping billions imprisoned behind the gates of Hades, but the one who has the keys to unlock those gates lets the prisoners out. That one is Jesus and he has been releasing a continuous stream of Satan's prisoners since his resurrection (which proves he has defeated death). That is why he promised his followers that he builds his Church, and the gates of Hades cannot overcome his Church. That is true even now. But when Jesus returns in glory to exercise his crown rights over the earth, then we will see him exercise his power of life for those who put faith in him, and render righteous judgment to Satan & Co.
Christ's death and resurrection has already, effectively, destroyed Satan, who is a dead demon walking - and he knows it. The sooner believers in Jesus believe that, the sooner they will discover Satan's power to just be a deception, based on lies, and they will be able to repeat 1 Corinthians 15:54-57, "Death is swallowed up in victory. O death, where is thy sting? O grave, where is thy victory? The sting of death is sin; and the strength of sin is the law. But thanks be to God, which giveth us the victory through our Lord Jesus Christ."
Power OVER death trumps power to cause death - any day! Jesus is both authorised to destroy his enemies and to raise to life those for whom he died.