> why do governments not make a habit of funding/creating really high quality tax software for businesses/individuals to use?
In the US, jurisdictional/funding issues are the biggest blocker. There is no federal sales tax, so the IRS can't use its budget to pay for this. State agencies are not going to be able to use their funds to pay developers to add functionality for a different jurisdiction, and ditto for counties/cities/special districts, which tend to have much smaller budgets anyways.
The best avenue would probably be something like ITOR (the funds that give USDS its wide remit to help any gov agency with their tech needs), but states and localities aren't always open to receiving this kind of help. (It did happen with unemployment programs during the pandemic, but the lawyers had to lawyer pretty hard to make that possible.)
That said, congress could fund this tomorrow if they wanted. Budgetary concerns apply to executive actions in this arena, but the whole idea sounds like it's necessary and proper for smooth interstate commerce.
In the US, jurisdictional/funding issues are the biggest blocker. There is no federal sales tax, so the IRS can't use its budget to pay for this. State agencies are not going to be able to use their funds to pay developers to add functionality for a different jurisdiction, and ditto for counties/cities/special districts, which tend to have much smaller budgets anyways.
The best avenue would probably be something like ITOR (the funds that give USDS its wide remit to help any gov agency with their tech needs), but states and localities aren't always open to receiving this kind of help. (It did happen with unemployment programs during the pandemic, but the lawyers had to lawyer pretty hard to make that possible.)