This will take a few minutes to read, but really explains the problem with this plan that Kevin McCarthy had to agree to put up for a vote in order to get into his position.

VAT is normal in other western democracies but in those other countries, there are also high income tax rates for wealthier individuals. In those countries, regressive VAT taxes are paired with with progressive income taxes. The GOP suggestion is to replace our not-progressive-enough income tax with a very regressive sales tax. Definitely a boon for the very wealthy and a burden for everyone else.

Those other countries also provide their citizens with free national healthcare, family leave, free childcare and more. Americans go bankrupt and die young while every other nation continues to see their citizens make economic gains and live longer.

The FairTax Act, GOP plan for 30 percent national sales tax, explained-
https://www.vox.com/policy-and-politics/2023/1/26/23563563/fairtax-national-sales-tax-kevin-mccarthy