No landline here, but it certainly has its uses and its reliability. A VOIP, Skype, etc is not a landline. A landline is a proper copper POTS. That means if the power goes out, your phone still works. A wired handset that doesn't depend on a battery will continue working indefinitely unless the CO gets shut down or a cable is physically cut.
All of these VOIP solutions work great under ideal circumstances, but offer little robustness compared to a real line. It is just a data signal traveling over the IP infrastructure and subject to all the potential issues that come with it, not to mention your phone stops working once the battery backup is out.
VOIP is worth it if it's free or extremely cheap, otherwise you're better off paying for a real line if you need it.