Battlecard: Why is flood insurance cost-prohibitive for low-income households?

1. High housing costs
2. Recent flood events
3. Reinsurance rates
4. Material changes in risk leading to increased premiums

I'm confused: these seem to apply to everyone, not just low-income households.

I thought the answer would be along the lines of
1. Low-income household tend to be higher flood risk
2. Not enough premium subsidies - government can force uptake, and do premium subsidy based on income, wealth, (protected characteristics) but insurers are limited
3. No capital to implement risk-mitigation measures. Low income households are already struggling to buy food, they can't afford to install backwater valves, basement sump pumps, maintain appropriate lot grading, clearing eaves troughs and extending downspouts
4. Limited competition between insurers - product offerings are limited because flood risk is not ideally insurable (is potentially catastrophic).