The more wealth inequality grows the less important 99% of the population is as consumers and the more important the 1% becomes.

Not as consumers, no. The 1% doesn’t consume more than the 90th percentile. They just park a higher percentage of their wealth in wealth-generating financial assets, which leech wealth from the rest of society.

We need a tax on all registered securities, (with exemption for the first $10 million owned by a natural person.) That tax should be paid not in cash, but in shares of the security: the IRS should slowly liquidate those shares over time, such that IRS sales never constitute more than 1% of total traded volume.

We further need the punitively-high top-tier tax rate we had for most of the 20th century. That tax rate pushed businesses to spend their excess income, turning it into other people’s paychecks. It discouraged the kind of wealth-hoarding investment that is stunting consumer spending.