You need to know the basic vim commands in the case you are stranded in a remote server and need to modify a file. It is also handy to do quick changes to a file when you are in the command line.

I used to do software development in vim back in the day, but I don't do that anymore. Now days I use sublime for scripts and an IDE for larger projects.

My recommendation. Commit the basic commands to muscle memory but you don't need to be a power user.