1. Online services are ephemeral

A business can at any time:

• Shutdown a service
• Go out of business themselves and take all of its services down with them
• Paywall a free service
• Change their API
• Cap the number of free API calls
• Change user verification requirements such as a CAPTCHA, email verification or 2FA

Unless you plan to indefinitely maintain your work by adapting it every time a service changes, it will eventually be bricked and turn your software portfolio into a graveyard. One day some poor aspiring programmer may come across your work, excited to learn from and be inspired by it, but instead be stuck in digital archeology and disappointment. Don’t do that.

2. Internet is a luxury

Not everyone has a reliable and speedy internet connection. Not everyone can afford to buy another phone plan for their electronics project to have a constant internet connection. Make your project portable and reliable by making it run locally.

3. Privacy

If you don’t value your privacy, a better debator than me has to convince you to. If you do, it should be obvious why an offline solution is better.