Peacock's Tail (signaling)
the flex only works because it costs you something
Grounded in the research on Wikipedia: Peacock (signalling) / Fisherian runaway / Handicap principle (Zahavi)
step 1 - name it
A peacock drags around a massive, useless, predator-attracting tail. Survival-wise it's a liability. That's the whole point: only a genuinely fit bird can afford to carry that handicap and still be alive. The tail isn't pretty for fun, it's an honest ad. Your version is the watch, the car, the unbothered flex. The signal works because it visibly costs you.
step 2 - the science
Darwin (1871) was bugged by the tail because survival selection couldn't explain it; he proposed sexual selection. Fisher (1930) modeled "runaway": a preference and a trait amplify each other into absurdity. Then Amotz Zahavi (1975) dropped the handicap principle, signals are believable precisely because they're expensive to fake. Mathematician Alan Grafen proved the model holds in 1990. This is real, load-bearing biology, not pop-sci.