Sascha why would it matter on which account you generate interest? The amount of interest is the same as bunq considers your total budget. If your money would only generate interest while being stored in a savings account then you're basically losing money compared to the current situation.
bunq has implemented some small tricks to make the savings account different from a regular account; you do not have the pay/request buttons once you've selected the savings target. Instead there are only buttons to withdraw all money and to add money. Withdrawing all is used to demotivate you to quickly withdraw a small amount of money to buy "extra candy" (or other things that could wait). The idea here is that you really save, and once achieved you withdraw all the money at once such that you can buy what you're saving for. As it is your own money bunq allows you to access the funds for cases like emergencies. In emergencies you can still connect your card to the account such that you can spend the money easily. The options are only a bit more hidden, to demotivate it. I think it's great that I can still use the account like that when the situation requires it. Furthermore it just a matter of discipline I think to not spend the money on other things than what you're saving for. 🙂