No, they're not just a wealth tax.
They are a disincentive to saving. The capital used to invest in new production (aka economic growth) comes from saving.
This policy (long dreamed of by Keynesians) will result in more economic activity and less investment. Economic decline.
That is the whole purpose, to reduce incentives to save and increase them to spend, to consume.
Obviously the saving-spending ratio is way out of balance in EU.
Those EU citizens are hiding their $$$.
That is why they are going cashless.
Cash in EU is like guns here, a threat to the powers.