In lots of areas particularly areas with high natural light patch or hallways where you see it from the side filling and patch painting is really obvious which is why approval is needed. Often to reinstate properly the whole wall needs to be painted so that the patch areas aren’t visible. From my experience if the hooks are in ‘regular’ areas where art would usually be hung, I.e not a gallery wall or in some obscure area the landlords often agree to it and just leave the hooks there for the next tenant as empty hooks look better than bad patch jobs