From Preston Brashers’s report, the three Bs appear to stand for “Build Bureaucracy Bigger”:

The Build Back Better Act has several provisions that make Congress less accountable for U.S. tax policy and give unaccountable bureaucrats more control. The act would (1) give the IRS more regulatory authority, (2) task IRS agents with finding new revenues, (3) allow a nonprofit organization to set tax rules, (4) allow the OECD to influence U.S. tax policy, and (5) force a future Congress to pay for this Congress’s fiscal irresponsibility. Congress should reject this misguided proposal.

Brashers gives several contrasting suggestions, such as simplifying the tax code and reversing the growth of the bureaucracy, especially the IRS.

I fear, however, that we’re already past the point that realizing the monster we’ve built is a plausible first step toward reversing it.