Revelation 6:2-8 are echoed in other parts of Revelation.
Revelation 6:2, first rider, on white horse, Jesus has a crown.
Revelation 14:14 "Then I saw, and look! a white cloud, and seated on the cloud was someone like a son of man, with a golden crown on his head and a sharp sickle in his hand."
Revelation 19:11-16 "I saw heaven opened, and look! a white horse. And the one seated on it is called Faithful and True, and he judges and carries on war in righteousness. His eyes are a fiery flame, and on his head are many diadems. He has a name written that no one knows but he himself, and he is clothed with an outer garment stained with blood, and he is called by the name The Word of God. Also, the armies in heaven were following him on white horses, and they were clothed in white, clean, fine linen. And out of his mouth protrudes a sharp, long sword with which to strike the nations, and he will shepherd them with a rod of iron. Moreover, he treads the winepress of the fury of the wrath of God the Almighty. On his outer garment, yes, on his thigh, he has a name written, King of kings and Lord of lords."
Second horse, "a fiery-colored horse, and it was granted to the one seated on it to take peace away from the earth so that they should slaughter one another, and he was given a great sword."
Revelation chapter 9 tells about battle and figurative killing.
Third horse, "look! a black horse, and the one seated on it had a pair of scales in his hand. I heard what sounded like a voice in the midst of the four living creatures say: “A quart of wheat for a de·narʹi·us and three quarts of barley for a de·narʹi·us; and do not harm the olive oil and the wine.”"
Revelation 7:16 refers to hunger figuratively...
"They will hunger no more nor thirst anymore, neither will the sun beat down on them nor any scorching heat, because the Lamb, who is in the midst of the throne, will shepherd them and will guide them to springs of waters of life. And God will wipe out every tear from their eyes."
The fourth horse, "a pale horse, and the one seated on it had the name Death. And the Grave was closely following him. And authority was given them over the fourth part of the earth, to kill with a long sword and with food shortage and with deadly plague and by the wild beasts of the earth."
Revelation 9:18-21 ties in figurative "killing" with stopping certain behaviors...
"A third of the people were killed by these three plagues, by the fire and the smoke and the sulfur that came out of their mouths. For the authority of the horses is in their mouths and in their tails, for their tails are like serpents and have heads, and with these they inflict harm. But the rest of the people who were not killed by these plagues did not repent of the works of their hands; they did not stop worshipping the demons and the idols of gold and silver and copper and stone and wood, which can neither see nor hear nor walk. And they did not repent of their murders nor of their spiritistic practices nor of their sexual immorality nor of their thefts."
The plagues of Revelation on Babylon the Great during the 3 1/2 years of the great tribulation "kill" many people to their former false worship so that they come to serve God in truth. Jesus talked to the congregations in chapters 1-3 warning them to repent of unscriptural practices, "So repent. If you do not, I am coming to you quickly, and I will war against them with the long sword of my mouth."
The wild beasts of the earth are governments. It is by means of the governments that Babylon the Great will be eaten up.
The Bible shows that the four horsemen are just another way of describing the 3 1/2 years of the great tribulation.