There is still an advantage to have local backup or should I say at least three disadvanteges to not to.

1. Network issues

2. Discs on the backup (3rd party)

3. Timehandling as this 3rd party backup software usually backs up everything else as well.

So not having local backup can get you wishing you have had.

I use local backup to discs connected to SQL server and then let 3rd party backup software take backup on those.

Very secure and nice if you need to restore quickly.