I heard someone on The World at One saying the Labour candidate hadn't bothered much with doing interviews but he and his campaigners did do a lot of knocking on doors and talking to potential voters. Simple common sense, surely? There seem to be huge numbers of people now who don't read a newspaper and never watch news on terrestrrial TV or listen to news on the radio. All of those news sources are to some extent regulated and provide facts, albeit often spun in a particular direction. Many voters will, however, get 'news' directly from social media, YouTube, TikTok and so on, which are completely unregulated and unverified. If you want to get to these voters, tramping the streets is probably the best way.