I guess you have never been self employed or run a business. Income is not the amount of money that you "took in" it is the amount of money left after you subtract what went out from what came in. Just imagine this case. You cash a $1,000 check for somebody and give them 10 $100 bills. How much income did you make? Zero.
The reason that income taxes require voluminous returns is that determining income isn't simple. Accounting for expenses is complicated, and the government always wants to adjust the system so that they benefit from the ordinary economic decisions people make.
The best solution is less taxes. The smaller the government is, and the less of life it is involved with the smaller the amounts of money it needs to operate. The next best improvement is excluding as many kinds of activity as possible from taxation.
Your scheme would require you to maintain records of every time you sell anything. So if you sold your neighbor your old lawnmower for $50.00 you need to record that and pay the appropriate tax on it. And since you want to tax inheritances, you want to tax people twice on the same money. That means you need to track gifts between family members, because money given before you die would not be taxed but your family's inheritance would be. Which is why there is a gift tax in the USA.
The complexity in taxation comes from determining income, not calculating the tax.
Wrong.
I have run a business through the whole gamut of C corp, S corp, and private ownership. And been self employed.
You present a false premise.
Sales and inventory are not income. In fact, you are in agreement with the IRS which now demands 1099s for sales. You would not pay taxes on sales. You would on the amount of money you profit.
I know from experience that you can hide income with S and C corp gimmicks. Maskingtrue income as dividends at lesser tax rates, avoiding Social Security and Medicare taxes using alternate income schemes, etc. You can also hide income- in-kind by using your company car etc. for personal use but charging it off to the company.
Sorry, but you are no different from the other beneficiaries of tax laws. You just don’t want to lose your benefits.