Why should customers need to care about a store’s employees tax bracket

Because that's the shithole we live in. If you don't like it, take your head out of your ass and crucify a politician or move

From 2025 to 2028, in a specific list of qualified occupations, as long as your AGI is below $150,000.

Is there something about serving people food that means you should get a tax break? Or is that just a holdover of cash tipping to kindly get servers to actually declare the full value if their tips as wages instead of just saying they magically weren't tipped all year

IIRC it was naked vote-buying.