The DoF has consistently shown itself to be reluctant to let savers and investors off the hook, so I can see why they prefer a Swedish ISK to a UK ISA structure.
When you see "annual tax of 1%"... it's worth exploring what that would amount to (your mileage varying depending on your situation.)
ISK you can stick in as much as you like. After the tax free allowance of 300,000 SEK (about €28k today) you pay this annual tax that comes in somewhere in and around 1% - it can move depending on government borrowing costs - on the entire fund value over 300,000 SEK.
ISA you can stick in £20,000 (about €23k today) per annum and all the gains are tax free.
On a like-for-like basis, if you invested €23k per annum to an ISA vs an ISK type product for 20 years, getting 8% annual returns in a straight line after fees, your €460k of contributions would translate to €1,137,000 in an ISA type product and €1,011,000 in an ISK type product - about €80k lost to tax and a further €46k of lost investment gains from the tax drag.
In this scenario, it's a tax & drag of 18.6%.
The world doesn't work in straight lines, though. So a year where you are -5%, you could be -6% thanks to the tax (assuming you've a lot saved over the tax free allowance.) That could have material downstream impact on your total "tax & drag" rate.
Overall an ISK strikes me as a wealth tax in disguise while an ISA is a true savings friendly product.
I wouldn't be surprised if the DoF introduces an ISK with both an annual and an upper contribution limit, to give themselves the best of both worlds.
We'll be better off than under the current system, but not as well off as they are in the UK.