Beyond the content, design can establish how trustworthy a website is. if it looks as if it was out together in a hurry by someone who doesn't care about the details, it's not going to inspire confidence. Even colour will break the illusion of accuracy if there hasn't been enough consideration for contrast, pairing, and accessibility. The flattest primary colours resemble something made by fisher price.
Two identical sources of information, one presented in comic sans and the other ins a serif font. Which one is going to feel more trustworthy?