Focusing on one brand can help you build strong authority, which means people trust your opinion on that brand. It also makes content creation easier because you stay within one area. On the other hand, reviewing many brands gives you more options and a wider audience. This can bring more traffic if done well. A balanced approach can also work, where you start with one brand and later expand slowly. That way, you grow without losing focus. It depends on your goal and content style. Which approach seems more stable over time?