Yes, absolutely. Having a single person do what they want with a component involves risks but I think they can be managed.

Say the dev in charge of an important component of a service is struck by a bus and dies. The optimistic scenario is that the code was well enough written that people developing adjacent components (ie. components that interface with that of the deceased dev) can effectively take over development in the short term until a new owner is found.

A more interesting scenario is that in which the dev abused autonomy and the component is utter spaghetti. In all but the most extreme of cases, the component could be kept in maintenance mode as is for some time. This would block progress that relies on changes in the component, but allow the service to continue working. In that time, other devs could either untangle the spaghetti and refactor the code into something workable or rewrite it. In both cases a significant amount of resources would be spent, but this is a scenario that's unlikely to occur often and the fact that the component was owned by a single person places a soft cap on the size of the component (and ideally an employee would maintain a couple of unrelated components to ensure they can continue working if one service is deprecated) ensuring it could be replaced within reasonable time.