iStock; BIHalf of US renters spend over 30% of their income on housing, Census data shows.Skyrocketing home prices and rents, driven by supply shortages and high interest rates, are to blame.African-American and Hispanic renters are the most cost-burdened, with over half exceeding the 30% rule.For decades, financial advisors and the federal government have recommended that Americans spend no more than 30% of their gross income on housing.But as home prices and rents have skyrocketed in recent years, that so-called 30% rule is increasingly challenging to follow.