Is it good practice to copy and paste graphics from illustrator into indesign?

No.

For quick, one-and-done projects you will essentially file or delete after export or printing, it's tolerable. For any project over which you need control, the ability to go back and change or adjust source images, or which will be worked on in iterations over time, it's very poor practice. It also bloats the file size unless you spend (too much) time making sure the image is optimal before pasting it in.

Use drag and drop if you must, but paste... never. (Except in that maximum-expediency, throwaway-project mode.)