there were always a few key people who rose above that level (and there always will be). They usually carried the Company
So sometimes their hand does leave a hole.
Knowledge can be restored. Functionality can be redistributed. Skills can be taught. But there are some people, who do real black magic, and it can not be transferred or distributed. It simply appears by itself... or does not appear at all and fade. Everybody says "welll, what we can dooooo..." and continue the march ahead, but much more slowly, and sometimes even in wrong direction.
In modern world this magic ceased to appear at all. No room for it, from the very beginning, from kindergarten. Everybody taught to do as usual, to work in team, to fulfill requirements and execute commands - and finally they grow just to team members, sometimes team leaders, but never to pathfinders, inventors, breakthroughrers. But nobody notices this, as it is not a hole, but simply an absence of something unseen. Magic leaves this world - and nothing comes instead.
насчет hand leave a hole - это имеется в виду "опусти руку в ведро, вынь ее - осталась ли в воде ее форма?".