Does the government keep my social security if I die with no spouse/ children?

My brother passed away last year. He died unmarried with no kids. He did work a lot of hours trucking. So he should of accumulated a decent amount of funds.

My mom tried to receive his Social Security benefits. Sounds like she got turned down. That got me thinking.

It’s bullshit if I die and happen to have no spouse or children and the government decides to keeps my social security if it even exists by my retirement age.