We base our standard of living on what society says our income permits, but with more kids and tithing we actually have less disposable income than we think we do. A lot of us are chronically broke
So at the margins on things like tipping and whether to get appetizers we feel broke and hold back more.
Plus, because of tithing, fast offerings, and all the time we spend on callings, our moral need to feel like we contribute is always more than satisfied.
At least that's what I see.