Anyone who knows me, knows that I am a 50mm focal length kind of guy, and I use and appreciate different lenses for their different properties of how they render an image, or more specifically the background blur. Case in point, for the Leica M mount, I own and use three different lenses that are in the 50mm focal length.
Left: 7Artisans 50mm f/1.1
Center: Canon 50mm f/1.2 LTM
Right: Zeiss 50mm f/2 Planar ZM
Each has their own look from one another, and each will be used for different reasons.
While the 7Artisans and the Canon are very close in aperture, both have a VERY different look from one another. The Canon LTM has a much softer feel to the image, and gives the subject a classic glamour look; whereas the 7Artisans has a much contrastier look to it, but still has a super pleasing out of focus blur to it, but lacks the softness.
The Zeiss Planar is my lens for when I want sharp, clean and contrasty images, a good every day kind of lens; and it is also substantially lighter than the other two lenses, and smaller, so making it nicer for everyday kind of use.
When you come right down to it, different lenses for different uses.