More to the point, most people's Roth contributions have no effect on their tax bill, so there's no reason to ask the taxpayer to report them unless they need to for the saver's credit or something.
Yes, but for example: I could fund some relatives' Roth accounts when they weren't
earning income (e.g. when they're young children) so I'd imagine the IRS would want
some form of reporting. Likewise, when I FIRE, I can't simply move some excess
cash to a Roth when I'm not earning income, else I could shelter the gains illicitly.
If they don't have earned income, they aren't eligible to fund an IRA, Roth or traditional, even with gifted funds. I've heard of parents funding children's Roth IRAs WHEN the child has earnings, but not w/o earnings.
Am I misunderstanding something here?
No, you're not misunderstanding Roth contributions, but you may have
skipped over some of the context in this thread.
I was unaware that Roth contributions by the taxpayer were not reported
to the IRS and learned something new, thanks to @seattlecyclone.
The discussion then drifted to how the IRS would track
illegitimatecontributions to a Roth account, which they presumably do by
comparing the IRA custodian's Form 549 against the taxpayer's
reported 1040 earnings. Hence my comment about
"else I could
shelter the gains illicitly".