How to clear huge area in Minecraft
you can make an armor stand:
/summon armor_stand ~ ~ ~ {CustomName:"\"Bob\""}
then make it clear around itself, using an always active repeating command block:
execute at @e[name=Bob] run fill ~-100 ~ ~-100 ~5 ~100 ~100 air
then send it into space:
/effect give @e[name=Bob] minecraft:levitation 10 50
You could use WorldEdit, with which you can select and remove massive areas with a single command.