I'd hold my breath on this on until the UK make a cbdc, I'd imagine they'd put a 2-4%.inflation rate on a coin or at least produce another cbdc that has low inflation - afaik some gold coins are legal tender still (but they're worth more just to sell on than spend).
And yeah the US irs seems crazy compared with the uks hmrc - tbh my tax return taxes about 2 hours to fill in and its about 40 pages long but it is mainly checkboxes and filling in amounts - if you file wrong and they assume its an accident then its £10 a month you don't pay the tax for added to the bill (lower than a lot of interest rates if its high enough for them to investigate)...
On the one hand, technology makes it easier but for taxpayers technology in currency is very scary. If the government demands transparency of the public, there should be openness and convenience for the public to access and know the allocation and distribution of their tax payment money. When people can know and prove that the tax money they pay is right on target and used for the benefit of society, they will not look for a back door to "not pay taxes".