A nifty fifty is a critical lens for many photographers dabbling with various genres. From good portraits to food to landscapes and weddings, one can achieve images that match the human perception. It's also why many young photographers with a kit lens gradually shift to an f1.
We're always looking for lenses that can perform magic. If you want to shoot in extremely low light situations or completely obliterate the background in your images, you need a lens (or two) that can do these with ease.
Shooting with a wide aperture allows you to drastically isolate your subject from the background and play around with bokeh, making it a neat technique for portrait photography. However, it also comes with a cost: the focus tends to be sharp only towards the center of your frame.
Street photography, much like landscapes, nature and wildlife is generally a solo hobby niche for photographers. You can go out on the streets and just enjoy snapping images and documenting the city around you.