Software should attract people. They should want to sit down and use it.
Expressive aesthetics can help with this. Splashes of colour, bold style choices, novel visual design. All of these things stand out, and make software visually interesting.
But it’s easy to overdo expressive choices. The design should offer areas of visual interest and areas of rest. This way people will not feel overwhelmed.
Trends have their place, and should be relied upon if they’re appropriate. They’re a strong signal that the software is modern, novel.