Because some people like my wife who loves red wine, isn't allowed alcohol for medical reasons, she is also diabetic which counts out loads of othe nice drinks due to the sugar content, lastly when at a party or meal, when everyone else is downing a glass of red, she accually feels like she is joining in rather that sat there with a glass of water, which is what usually happens.
Alcohol free wine is getting better, it will probably never be as nice as real wine, but when it first came on the market, it was pumped up with grape juice and still far to sweet for her, but they seem to have developed a process to remove the alcohol and produced an ok drink that lets you join in.
If you are in Hérault this vineyard is just north of beziers, who do a passable non alcoholic wine.
https://lacolombette.fr/en/
Is it for me, no not particularly but I will probably have a glass now and again if I am driving, but i also have a wide choice of different non alcoholic drinks that would be too sweet for my wife.