The longer I follow some influencers, the easier is to see how it's all fake. For example when they promote one brand for ages when they partner up with them, saying their products are amazing, just to then change their tune. That seems to happen when they, for example, come out with their own products and at that point the other brands are not good enough. Why promote them before then?
I sometimes buy things promoted by influencers though but only if I really want it and I do further research into the products and compare reviews, prices, other available products etc