Good or bad Idea to change magento 2 core files?

Question

Why is it not recommended to modify the Magento 2 core files?

I'm guessing that when Magento 2 updates it replaces those modified files with the new files so it would be a best practice to create a extension/plugin instead?

Thanks

Answer 1

Definitively, in any framework it is a bad idea to modify core files. There is almost always some way to override native code. There are many reasons, the two main being:

• The risk to create side-effects on other modules
• The risk to see your modification wiped out when you update the framework

Regards