I have a bit of money in the bank. It's not there for investment purposes. It's there to be spent. I'd shop around if one place implemented this but wouldn't bust a gut doing it.
If you want to charge -0.5% of 100,000, that's 500 euros per annum. Which is a pretty large service fee. It looks smaller if you say it is a negative interest rate!
No worries, banks don't shy away from that kind of service fee. They just usually hide them by splitting them up into monthly fixed costs as well as penny and diming you for every bit of service on top.
Take a look at this price sheet, for example:
https://www.raiffeisen.at/eBusiness/services/resources/media/1021497204966-NA-1279548085059316048-1-30-NA.pdf
(the numbers will differ depending on the branch, but the pricing structure is usually pretty much the same)
Including taxes and ignoring compound interest they already charge you more than 0.5% in service fees for storing investments fonds by chipping away 0.039% plus tax on a monthly basis.
Luckily there are banks that focus on investments and charge much much lower fees. But most people simply get screwed over by their banks on a regular basis, no matter if they stay in cash or stocks.