Because they incentivize it. Some banks are better at incentivizing it than others. My bank for example, allows the highest daily limit (by a factor of 5x) if you use the app. Online banking has a lower limit, and cards lower still. I don’t appreciate them holding my own money hostage, but the sad reality we live in precludes me from having enough remaining mental bandwidth and effort reserve to commit it to fighting against it in such an empty and unwinnable battle. Money is a scam anyway.