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why lens of large aperture create physical problems on it but mirror of large aperture doesn't?

§   An aperture is a hole or an opening through which light travels.  If an aperture is wide, then uncollimated rays are admitted, resulting in a sharp focus only for rays with a certain focal length. The aperture also determines how many of the incoming rays are actually admitted and thus how much light reaches the image plane i.e. the narrower the aperture, the darker the image for a given exposure time.

§  An optical system typically has many openings, or structures that limit the ray bundles. These structures may be the edge of a lens or mirror, these structures are called stops. The size of the stop is one factor that affects depth of field. Smaller stops produce a longer depth of field, allowing objects at a wide range of distances to all be in focus at the same time.

§  If the stop is too large, the image will be distorted.

§  A larger aperture stop requires larger diameter optics, which are heavier and more expensive.

Larger apertures provide a much shallower than smaller apertures.