Hilariously there is a motivation to provide low value receipts for estate executors.
"That old bookcase? It was only worth a dollar so I sent it to Goodwill after his death, it wasn't in the will and nobody wanted it".
Now maybe an antique dealer could sell it for $400, meaning maybe the seller might have gotten $100, and now the estate executor is in trouble. But he died and there's three days to get all the stuff out of the apartment and nobody has set up an estate-paid-for storage unit (how long can you afford to store something only worth $100 anyway? If estate/probate process takes a year...) or prepared a deal with an antique dealer to immediately accept (and who's going to drive it over there, I don't have time?) and if its not disposed of in three days the building mgr will hire a very expensive per hour cleaning crew to toss it in the trash (at some expense) and deliver a hefty bill to the estate. And Goodwill gave him a receipt for a dollar so its documented at least. The Goodwill receipt at least proves the executor didn't steal from the estate by hiding the bookcase in her basement and selling it later on ebay for $400. As if she's young enough to know what ebay is.
An eventual audit that if they hit the anti lottery could cost them more than they could possibly save. Remember that you don't get to just deduct a donation from your taxes you deduct it from your income which lowers your taxes. For example if you ultimately pay about 30% of your income in federal taxes and you lower your income by 1000 you ultimately have reduced your taxes by $300.
Donations 5000 and up require the person you donated to to fill out a tax form for that donation so making up the numbers would require a confederate in the donating org to be willing to risk prison to enrich you.
Also remember that the bottom half of the country pays little federal income tax (because they don't make much of the income in America) and the top 10-20% has MUCH better legal tax avoidance strategies.
It's likely that some portion of middle income individuals could avoid a small dollar figure in taxes by inflating or even fabricating a string of small donations and presumably out of hundreds of millions of people a few do but you would have to make up a LOT of bullshit donations to make much of a difference but before you could actually save much money you would end up sticking out like a sore thumb. Yes Mr IRS auditor I totally donated over 1000 in goods to goodwill on 10 separate occasions over 2021 and I totally deserve the corresponding $3000 deduction!
On net its probably a small issue. At this point we have people making 6 figures + who just don't file tax returns and haven't been addressed.
"That old bookcase? It was only worth a dollar so I sent it to Goodwill after his death, it wasn't in the will and nobody wanted it".
Now maybe an antique dealer could sell it for $400, meaning maybe the seller might have gotten $100, and now the estate executor is in trouble. But he died and there's three days to get all the stuff out of the apartment and nobody has set up an estate-paid-for storage unit (how long can you afford to store something only worth $100 anyway? If estate/probate process takes a year...) or prepared a deal with an antique dealer to immediately accept (and who's going to drive it over there, I don't have time?) and if its not disposed of in three days the building mgr will hire a very expensive per hour cleaning crew to toss it in the trash (at some expense) and deliver a hefty bill to the estate. And Goodwill gave him a receipt for a dollar so its documented at least. The Goodwill receipt at least proves the executor didn't steal from the estate by hiding the bookcase in her basement and selling it later on ebay for $400. As if she's young enough to know what ebay is.