Wasn’t always the case. Vodacom network only started really falling apart in 2018-2019.
MTN was way behind on their network even as recent as 2015. They really seemed to have pulled a magic trick in the last 5 years from my own experience with both.
MTN far outstripped VC in network expenditure since 2015 somewhere, by something like 50%, and they made it work.
My Cell C 50 + 50 GB prepaid data bundle for R 500, valid for 180 days works on the MTN LTE network , and I won't complain. 25-60 MBPS down and up, latency 25-35, in a small rural town between the mielies, at least 250 km from any server centre. Although it needs a roof top aerial to achieve that., as the tower is a bit far, behind a hilltop.
"Now why would more people make use of Vodacom if their network is supposed to be not as good as that of MTN? "
There are many reasons why people stick to the same brand, or choose another network. Could be price of their packages, network quality, perceived value for money, word of mouth.
Customers ( and voters) in SA are rather conservative and traditional, they will not easily change networks. And then there are these strange ideas, misconceptions about brands and ownerships, and identity. I once talked to a neighbour here about the mobile networks, he was with VC for decades, and said in a clearly pejorative way : MTN is a BEE/AA company. I wonder if this is still true.
In a bit similar fashion, an owner of an independent cell phone shop that did contracts for a national company, forgot the name, that dealt with all 3 networks about 10 years back, told me, after I said I was with Cell C, in a rather disapproving way : "Those Arabs". Cell c was at that time still owne dfor 60% by Oger Telecoms from Saudi Arabia. Since 2017 Blue Label telecoms is the largest owner with 45%. Oger completely left SA.
My main reason for choosing Cell C in 2008 and later also for data, wast that they not only had good rates, value for money, but theit tower was much nearer than the VC/MTN one and resulted in a much better connection in this small rural town. Many people in this area complain about their VC and MTN signal, but they never switched to Cell C. Now Cell C stripped the local tower of their stuff late 2019. And I had also a horrible experience with a Vodacare centre around that time, not honouring a guarantee on a phone, and claiming falsely that the phone had liquid damage. And wanted me to pay for the diagnosis and the checking of the phone. I left the shop steaming, and my family turned its back on VC for ever.