That's not quite accurate; they had the Democrat House & Senate numbers to do so under reconciliation but didn't have the Dem votes, and it wasn't just Manchin & Sinema.
No one paid anywhere near 90%, or we'd have had an economic dark ages. The U.S. doesn't exist on some isolated astral plane of economics that you can simply jack taxation without hurting your competitiveness; among OECD countries, the U.S. is only middle of the road competitively, and was even less so before the 2017 TCJA.
While we're there:
A careful analysis of the IRS tax data, one that includes the effects of tax credits and other reforms to the tax code, shows that filers with an adjusted gross income (AGI) of $15,000 to $50,000 enjoyed an average tax cut of 16 percent to 26 percent in 2018, the first year Republicans’ Tax Cuts and Jobs Act went into effect and the most recent year for which data is available.
Filers who earned $50,000 to $100,000 received a tax break of about 15 percent to 17 percent, and those earning $100,000 to $500,000 in adjusted gross income saw their personal income taxes cut by around 11 percent to 13 percent.
By comparison, no income group with an AGI of at least $500,000 received an average tax cut exceeding 9 percent, and the average tax cut for brackets starting at $1 million was less than 6 percent. (For more detailed data, see my table published here.)
That means most middle-income and working-class earners enjoyed a tax cut that was at least double the size of tax cuts received by households earning $1 million or more. https://thehill.com/opinion/finance...enefited-middle-working-class-americans-most/
Odd outcome for "tax cuts for the rich", and perhaps why Biden couldn't raise enough votes to reconcile repeal.