When using the /data command to detect attributes, it doesn't list all of the attributes that it probably should. In previous versions of Minecraft, it would list all of an entity's attributes if they had any, but in the 1.16 snapshot versions, it lists less than it should. An attribute that doesn't appear in the 1.16 snapshots version only seems to appear if its tinkered with, like with the /data merge command or the /attribute command.

Normally it would show all of an entity's attributes, but in the 1.16 snapshots, from what I've seen, it only gives generic.follow_range, generic.knockback_resistance, generic.movement_speed, and attributes that are unique to specific mobs, like zombie.spawn_reinforcements. This is a problem because I can no longer detect mobs that have an attack damage attribute with the @e[nbt={Attributes:[

]}] selector and other things of this sort.

This is what it should look like:

This is what it looks like in 1.16 pre-release 3

To do this, I just typed in
/data get entity @e[type=zombie, sort=nearest] Attributes