Here is an article about who is the best Pyro character in Genshin Impact including the reason why they are the best characters that has Pyro element.
1. Hu Tao
Hu Tao is one of the best Pyro DPS in the game that uses Polearm. Because of her high damage output on her EM Burst, she is easily the best on this list, and her AoE deals a lot of DMG for surrounding enemies making it easier to clear Abyss or a group of enemies.
Bennett is one of the best supporters in the game that have the ability that heals and buff all teammate ATK and His Elemental Burst is easy to recharge when he uses E skill and to get more buff from his burst you have to increase his base ATK because it's base on his base ATK. He is also suitable for all team comp.
Even though, Xiangling is 4 stars she can be the best Sub-DPS in the game thank to her AoE Burst that summons a Pyronado around her dealing Pyro DMG to nearby enemies. Both of her skills are still active even if you switch to another character which is why she is the best at Sub-DPS Role.
Klee is a good DPS as well as Sub-DPS 5 stars character. She is really good at applying Pyro element on enemies as well as dealing AoE DMG on her burst and it breaks into small particles which is great to pair her with an Anemo character like sucrose to group up enemies and take advantage of those particles to deal more pyro DMG.
Yoimiya is a good DPS bow user who priority dealing with huge amounts of DMG single target enemies. Without using skill, she can apply Pyro DMG by using charge ATK. However, it is really hard to deal with AoE DMG since she is a long-distance play-style character.
Pyro is an element the strongest element in Genshin Impact. Most of the Best DPS characters have the Pyro element and it is easy to react with another element to create high DMG output. These characters are selected based on their DMG and Utility in combat as well as correct build.
End of Top 5 Best Pyro Characters in Genshin Impact.