A barricade only buys time. So the wealthy buy more barricades.

Siege Zombie

Tap three untapped creatures you control: Each opponent loses 1 life.

Innistrad Remastered

The List

Innistrad: Double Feature

Innistrad: Midnight Hunt

Since Siege Zombie's activated ability doesn't have a tap symbol in its cost, you can tap creatures that haven't been under your control since your most recent turn began (including Siege Zombie itself) to pay the cost.