//Landlines as we know are being phased out and very soon everyone be using VOIP although they may need an adapter if they want to continue using their existing phone.//
There seems to be confusion over terminology here.
Currently most people receive their telephone and internet services over a landline (that is, a pair of physical wires - or sometimes either in whole or in part a fibre optic cable - running from the telephone exchange to their premises). The data transmission for their internet service is provided over those wires but is actually facilitated by a system known as "Asynchronous Digital Subscriber's Line" (ADSL). It is termed "asynchronous" because the transmission speed from the customer to the exchange is far slower that from the exchange to the customer. This is because the information the customer needs to send (to, say, find a certain website) is usually far smaller than the information the website needs to send to the customer (say, to stream a film).
Alongside this data transmission (but sent over the same pair of wires) are sent signals transmitting their voice when they make a voice call. At present most customers' voice calls are dealt with by the Public Switched Telephone Network (PTSN) - sometime known as "POTS" (Plain Old Telephone Service). These calls are connected in response to the numbers the caller keys in to his phone's keypad and are switched by telephone exchanges.
The programme which is termed as "ending landlines" is not really anything of the sort. Customers will still need a pair of wires connecting their premises to the exchange. What is happening is that the PSTN is gradually being wound down and instead voice calls will be facilitated, as you say, by "VOIP" (Voice Over Internet Protocol). The PSTN uses "channel switching" where a dedicated "channel" between the two participants is set up when the call is initiated and it remains exclusive to them for the duration of the call. VOIP uses "packet switching" where packets of data (in this case the digital translation of the participants' analogue voice signals) are transmitted in chunks, but not necessarily over an exclusive or dedicated connection. (That's it in very simple terms).
Telephone users will notice no difference between the two as it's simply the method of transmission that is being changed. But they will still need a "landline" to make such calls.