Actually there are several instances where debt wins.
Let's say you are retired and to get that $50k trike, you have to withdraw from your IRA. Now you have an income tax liability that you would not have if you financed at, with today's rates, probably 5% or less.
Or you take the money from your after-tax account, which could mean selling stocks at a loss (not good), at a profit and now capital gains taxable, and lost opportunity for further growth.
Every single mutual fund or stock I have has grown over 15% just this year. And with good credit, most would be more than "living within their means" if they chose to finance, which I would.
Not everyone's circumstances are the same.