An umbrella works above a renters policy
The product is not tied to owning property. It sits above the liability on your renters policy and your auto policy, raising both. Tenants assume it is a homeowner’s product because that is how it is usually sold, and the assumption leaves the most exposed households uncovered.
Auto liability is the real driver
For most tenants the realistic route to a claim beyond their limits is a serious at-fault collision, not something at home. That exposure is identical whether you rent or own, and so is the consequence.
A judgment follows earnings, not addresses
Having few assets today does not end a claim. In Arizona a judgment can be enforced against future wages for years, which for a young household is a worse outcome than losing savings they do not yet have.