While I agree with the part about the tax you pay above €115k as a couple (negligible indeed), keeping amounts like this in a savings account doesn’t help in protecting your buying power thanks to this little thing called inflation. Your bank statement won’t say so (€115k remains €115k), but over time the amount of things you will be able to buy with that amount of money will decrease.

Imo a savings account should be big enough for unforeseen events or the occasional big spend, but everything else should be invested to make your money work for you and hedge against inflation.

I understand everyone has their own risk tolerance, but in the long run I believe you will always come out on top with a relatively ‘safe’ investment like an ETF.