Design

At times, I find myself caught between the decision of opting for a "trendy design style" versus a "functional design style."

meliorism: the belief that humans can make the world a better place

An example could be an eCommerce platform.

For a trendy design, one might consider using vibrant colors that are popular at the moment, along with stylish typography. Making the website visually appealing and catching users' attention.

To balance both, you could incorporate the trendy colors and typography in a way that doesn't compromise the readability of important information.

Bingo. I like the quip “decoration is not design” but there’s something to be said for aesthetic appeal

Yeah, aesthetic appeal is attractive, but not sustainable if the UX can't complement its attractiveness.