I think that is an overly pessimistic view of the future. There are many great people alive today, and far many more yet to be born.
To make the declaration that President Trump is the best that ever will be…
That said, since leaders are often sized by the challenges they face, I should hope the future never faces the type of existential threat POTUS faces, today - and the leaders of the future, great as they may be, can have a much less dire set of conditions defining their role.