Income: $30,000
Standard Deduction: -$5,700
Taxable Income: $24,300
Tax on first $8,375 @ 10%: $838
Tax on remaining $15,925 @ 15%: $2,389
Total Tax: $3,227
Did you look up what current tax rates are? That person would pay about 37% more in tax under your plan ($4,409 vs $3,227). They'd have to put nearly $5,000 per year into savings just to end up with the _same_ tax burden.
On the other hand, a person making $250,000 per year and spending $150,000 of it would end up paying less than half of what they do now ($65,736 vs $32,009). Even if they spend every penny, they'll still only pay $55,000 for a savings of over $10,000.