One of the most common pro photography effects is to blur the background using a bokeh effect. It's beautiful, but most importantly, it helps with storytelling by doing the following
it focuses on what's important, your subject by creating an uncluttered background
it gives a subtle notion of the context, the mood, the place where your subject is situated without creating too much noise
While you would need expensive gear to create a blurred background with traditional photography. PhotoRoom makes it easy. You just need to do the following
Start with an image
Select the template with a blurred background in classics
Alternatively, when editing, you can always do the following
Tap background
Tap blur
Select one of the blur effects and adjust its amplitude
Here is a video that demos the previous steps.
Going further, a few things that can work really well combined with a blurred background:
Create a light blurred white outline
Lower the brightness of the blurred background