It can be less regressive depending how it’s done. Poor people spend much larger percentages of their income on essentials like food, clothing (non luxury), and rent which can all be made tax free. It can then actually tax people who do things like take out massive loans to cover their expenses while not technically earning an income.

Washington state has also never had an income tax and uses sales tax but makes many essential items tax free to try and be less of a burden on the poor