As a creator, it is important to show brands that you care by building strong relationships with the ones that support your channel. For one, the income brands offer can help you turn YouTube into a full-time career. Secondly, your fans want to see you promote brands you believe in. I always recommend creators find a handful of brands they truly love, build genuine relationships, and then come to mutually beneficial long-term partnership terms. Jumping from brand to brand causes distrust in your audience and in my experience, that distrust leads to poorer results for brands. It is a negative cycle you want to avoid at all costs.