Taxing businesses on gross revenues (what “no deductions” means) is a huge bias in favor of vertical integration and large conglomerates. If I’m a small company and participate in a chain of 8 companies providing a good or service, there is a large multiple of tax paid on that good as compared to a competitor who manages to do all 8 things in a single company. (This is why VAT taxation works better and is more common…
I wonder if the article perpetuates the confusion about "deductions." I run a small business and use Schedule C on my tax return. Basically, Schedule C has you write down your revenues, and subtract your costs. The difference is what ends up in the income section of your main form. "Deductions" come later in the form.
Costs of Goods Sold are deductible: https://www.irs.gov/publications/p535#en_US_2021_publink1000...