Why do pre-tax FSA programs in the U.S. include contribution caps, when the funds in the account must be spent within the contribution year?

In 2026, the annual household contribution limit for Dependent Care FSAs is $7,500, a significant increase from the $5,000 limit in 2025. While we welcomed this increase, it does not come close to covering the $30k+ my wife and I spend per year on childcare for our two young children. My understanding is that, at least when it comes to childcare, $7,500 rarely covers a family’s annual expenditure.

I understand that placing limits on untaxed contributions to retirement investment or savings accounts will prevent the hoarding of untaxed wealth. FSA accounts (not just DCFSAs), however, are “use it or lose it.” This means they cannot be used as a way of indefinitely storing or investing untaxed dollars, because the money *has* to be put back into the economy. I assume these programs exist to ease the burden on essential spending for working people on an annual basis, so why have a cap at all? Is there any data on how much revenue the IRS would forego if it eliminated FSA contribution caps?