Historically, congress always passed a one-time bill to retroactively pay the federal employees after each shutdown.

Because it turns out not paying your workers is extremely unpopular, especially if you want to retain them as workers in the future. Most people (federal workers included) are living paycheck-to-paycheck and can't financially weather a furlough - they still need to pay rent. The federal government would quickly find itself unable to attract employees given how often shutdowns occur.

After 2019, congress passed a law that guaranteed back-pay for future shutdowns: https://en.wikipedia.org/wiki/Government_Employee_Fair_Treat...

So large numbers of government employees don’t quit when congress can’t get its act together and keeps passing sort term bills.

It’s all fine to posture, but politicians hate long term consequences when they can use other people’s money to avoid them.

Because everyone involved is in on the grift and the money comes from the taxpayer's budget.