I once had to travel over 2000 blocks to find a horse after an hour of finding and killing pillagers just for the horse to step in front of a zombie right as I went for a crit with a netherite sword. The horse was killed instantly. I was so pissed that I just went on a rampage killing every hostile mob in sight, zombies, skeletons, creepers, endermen, witches, everything. I grinded 30 levels in 1 night.