Because you're being a good socialist citizen and paying for someone else.
See, if I were a bazillionaire I'd pay for someone else. Money is like a drug - the more you have, the more you want. Most rich people operate on greed and moremoremore. Trump was the exception - he donated his president salary to charity - but I've never heard of any other bazillionare politician doing that. Joe Biden certainly didn't, even as he was getting his palm greased from Ukraine kickbacks.
But I've never had big money. Grew up poor and managed my adult expectations accordingly. When I was doing really well financially (by my meager standards) my favorite thing to do was give it away and buy people presents.
But I wouldn't just leave that money in the government coffers because they've shown to be poor stewards. I'd draw it and give it away on my own terms. That waitress who was so sweet and efficient? Here's $1000, sis. The Publix deli guy who is so patient with my order and cleans his slicer between products - here's a little somethin' for ya, bud.
I don't really understand rich people who buy multiple mansions and ridiculous art and yachts and such. It's more fun to use that money to brighten someone else's day.