Put simply, they are spells that you are likely to see in a game of commander
Tezzeret, Master of the Bridge #275 War of the Spark Change Version Tezzeret, Master of the Bridge Legendary Planeswalker Tezzeret Creature and planeswalker spells you cast have affinity for artifacts
Because discovery is such a big part of the appeal, many players prefer lobbies that categorize games by theme, volatility, and features like expanding wilds, buybonus functionality, or cluster pays
It also doubles any stun counters or -1/-1 counters put on your creatures, regardless of who controlled the effect
Its still only 1 power for when you turn the corner and start attacking again, but at least the increased toughness means your opponents chump more often than trade, and its a semi-permanent buff