Yes—sometimes, but not mainly for shallow depth of field.

For landscapes, a faster lens can help in a few practical ways:

• less vignetting at the same shooting aperture: for example, a lens designed to open wider often shows less corner darkening when both lenses are set to something like f/4 or f/8.
• potentially better image quality when stopped down: many fast lenses are designed to perform well wide open, so they can be very strong at common landscape apertures like f/5.6–f/8. That said, this is not automatic—some slower lenses can also be excellent.
• easier focusing: a brighter viewfinder helps manual focus, and autofocus may work better in low light if the camera can take advantage of a faster lens.
• more flexibility in low light: at dawn, dusk, or in windy conditions, a wider aperture lets you use lower ISO or faster shutter speeds, which can reduce noise and motion blur.

That said, maximum aperture is not the main thing to prioritize for landscapes. Edge-to-edge sharpness, distortion, vignetting control, focal length, and overall lens quality usually matter more. If you mostly shoot stopped down, a sharp lens that performs well across the frame may be a better choice than simply choosing the fastest lens.