In Minecraft 1.16 I can’t figure out how to check if an entity isn’t in the air
Solution 1:
I'm not sure if I'm missing something pretty obvious but you should just be able to do:
execute as @e[type=husk,tag=remake] if data entity @s {OnGround:1b} run tag @s add looted
This adds the tag looted to any husk with the tag remake if they are not touching the ground