TLDR
The debt-to-GDP ratio of the US government is projected to go up to unsustainable levels, so high that it may introduce Fiscal Dominance. The government has two ways of solving this: high inflation with an inflation tax (the government owes less if the currency its debt is denominated in decreases in value) or reducing government spending. The former is more likely to happen, which may cause Financial Disintermediation and lead depositors to seek other forms of banking and deposit (interest) returns.