"tax prep" isn't something I've had to ever think about for the UK system. I don't have to buy software, I don't have to pay anyone. I get my wage, it has my taxes taken out. That's it. I don't need to keep receipts, I don't need to work out how much mortgage interest I've paid, etc.
My individual situation is calculated, by the tax authority and rolled into a "Tax code" which acts as the personal allowance. This then feeds into payroll which pay you net of tax.
If at the end of the year, the tax authority (not you, this is automatic without a form being filled in) spots an over or under payment, they adjust your tax code for the next year to recoup or refund the difference. No cheques in the post, no forms to fill in. Just automatically happening in the background.
Meanwhile for the US, I need to fill in 2555, 1040, and other forms. These aren't "5 minutes", they're slow, and more importantly error-prone, as they get you to add up different numbers rather than just asking for the information needed.
No human should ever have to answer the series of questions ( this is legit, from the current 1040 ) :
24 Add lines 22 and 23. This is your total tax
Where Line 22 is:
22 Subtract line 21 from line 18. If zero or less, enter -0-
Line 21 is of course:
21 Add lines 19 and 20
And 18 is:
18 Add lines 16 and 17
Where 17 is:
17 Amount from Schedule 2, line 3
Where that is an entirely different form.
The only purpose I can tell for this ridiculousness is to give scope for people to make mistakes.
A form should collect raw information, not put the burden of calculation shouldn't be on the form-filler in a world where computers exist.
The data is already on the form. What purpose can that solve except opening up a possibility for someone to accidentally commit tax fraud?
You're missing the point suggesting it should be "a couple of CSV files". No, it shouldn't be any filing at all.
Demand change, demand simplification of the tax system, and demand zero-filing solutions for regular employees.