<<I do think that pilots are able to safely land and taxi to the gate without the assistance of ATC, >>
Well, better you than me! Taxy in alone, without help... but watch for the busted light fitting that'll shred your tyres... or the maintenance vehicles alongside the taxyway... and all and all.
<<the Swiss controller was allowed to be alone at his station >>
Happens all the time, all over the world, especially at airfields or their associated approach controls.