It will be interesting to see the details but if we precisely follow the Swedish model, it won’t really be an advance on where we stand today.
I am disappointed we are not going down the ISA route, but even the ISK-type model would still be a significant improvement on what we have now.
Let's say you invest €10k in an equity ETF, it returns 8% for the year, that gives you €10,800 at the end of the year. If we apply a 1% tax on that, that's €108 of tax due.
€108 tax/€800 total gain is equivalent to a CGT tax rate of 13.5%, which is significantly better than the 38% exit tax on ETF's and even the regular 33% CGT rate. If part of the 8% return came from a dividend, it's even better again for higher rate income tax payers whose investment income would be taxed at the marginal rate.
The scheme also simplifies everything for both the consumer and the government. The consumer no longer has to track income received, the cost basis of positions, loss carryover, etc. You presumably will get a single tax bill on the amount in the account at the end of the year. It should also be a win from the perspective of the government and tax collection. They will have a more predictable stream of revenue whose complexity of collection will be very straight-forward (the onus will probably be on the provider to report on what an account is due at year end).
The only downsides? This scheme really only work for equity-type investments where you would expect a higher return. If you were to keep your money on deposit and earn 3%, once the government apply the 1% tax, your effective CGT rate is just over 33%.