The only 1099 that most people will get, even with meaningful savings, meets this description.
1. https://www.pewresearch.org/internet/2021/12/08/the-state-of...
Yes, most people with more than a few hundred bucks in savings accounts will get a 1099-INT, but a lot of people just use checking accounts and if you're at a big bank like Chase even savings account interest is so low you still might be under the $10 threshold.
The average American's investments (if they have any at all) are in retirement accounts so they'd avoid those taxes too.
Dividends and capital gains are not mentioned, and presumably not eligible.
For example, how many of those respondents in the Gallup poll answered yes only because they have a Simple IRA? For those respondents, their contributions don't preclude them from taking the "simple tax" branch when filing taxes. (That's the "simple" part-- well, one of the simple parts, at least for the employee.)
Moreover, there were some changes to simple IRA administration in Secure 2.0 act that make automatic enrollment mandatory (for the employer to do 3% matching or whatever). So the category of respondent I mentioned above-- who technically has a brokerage account but can file simple taxes-- is likely to grow quite a bit in the next few years and decades.
Edit: I'd also be interested in how many people with simple IRAs contribute anything more than the 3% matching-- I'd bet its more than a majority. Perhaps that could change now that Secure 2.0 lets them contribute to a Roth IRA.
