Parents have concerns about Scalable Capital

Hi, all of my money (99%) is in Scalable Capital's overnight money for the 2.5% interest. Also a small savings plan on the FTSE all World. I am a student and have small expenses of less than €50 per month, which I get paid in pocket money in cash. If I need something larger, I'll get it from Scalable within 24 hours. I also have ETFs from them in my portfolio that I transferred via portfolio transfer. But they serve as a long-term investment for 20 years + you