This was the most common and reliable method in 2021. Instead of installing a modified version of Meteor, players used a version compatibility mod.
Why specify "2021"? Because cheat detection evolved rapidly. In 2021, anti-cheat systems like (Hypixel), AGC (AntiGamingChair), and Verus were significantly less sophisticated than they are today. The 2021 backport of Meteor Client often bypassed basic reach checks and movement prediction. meteor client 189 download 2021
Since there is no native 1.8.9 version, the official and safest method to use Meteor on older servers is through version-switching mods This was the most common and reliable method in 2021