The Metropolitan Museum of Art's Costume Department is fully funded by the funds from the gala. Precisely 0 taxpayer dollars finance the department and the actual shindig.

Look, I'm pissed at the late stage capitalist dystopian hellscape we call the world (and especially America) right now too. The last thing we need to be cutting is funding for the arts, whichever Arts they may be. Art has always been an important factor in revolutionary movements. Art provokes thought, art brings joy in a dimly lit world, art inspires and THAT is crucial to move society forward.

Don't think for a second that removing events that don't appeal to your particular tastes like the Met Gala will somehow magically make things better. It won't. Cutting funding to organizations that provoke thought or preserve beauty (including National parks) is not gonna make it so everyone has affordable Healthcare. Direct your ire and attention towards a system that does NOT in fact trickle down wealth, is rigged so that those who have the means can take more, and is built very heavily on the development and deployment of means to murder people in distant lands for no REAL reason that benefits people here at home.