Best Tank in Shadowlands - Tier List

Stagger is so strong for progression raiding. It allows the tank to spread out the big dmg spikes and gives healers more breathing space for raid and screw ups. 

Meaning they can handle heavy dmg and several enemies. 

Also gives 5% physical dmg buff to raid. 

Can handle several enemies.
Has spell dmg defense
Has self-heal.
Has Mass-Grip
Has Anti-Magic Zone (really strong Raid defensive)

Has Raid survival abilities
Has Raid defensive abilities
Has Immunities
Can solo interrupt an enemy. 
Can buff the raid with 3% dmg reduction. 

Protection Warrior

Has many defensive abilities.
Mass spell reflect legendary got nerfed

Vengeance Demon Hunter

Metamorphisis got nerfed in Shadowlands and throughout the beta. 

Windows with no defensive Mitigation. 

Guardian Druid

Problems against magic burst dmg.
Long cooldown on the main big defensive (Survival Instinct)

Very high dmg dealer
Very high self-sustain
Very good mobility
Defensive mitigation must be timed well. 

Has 3 types of builts to go more offensive or defensive:
Kyrian Sigil Build 
Spirit Bomb Build
Fiery Brand Build

Very high dmg dealer
Overall good defense against several enemies, spell dmg, heavy dmg and physical dmg.
Party buffs and survival. 
Good Self-sustain

Celestial Brew got nerfed and must be timed perfect.
Dependent on healer (low self-sustain)
Good utilities
Very good mobility

Strong utilities
Battle Rez
Immunities
Good defense against several enemies
Good defense against spell dmg
High self-sustain

Very low dmg dealer
Bad Self-sustain
The Thrash legendary (Ursoc´s) got nerfed. 

Coming to shadowlands with no "BFA borrowed powers" nerfed it drastically.