"...which is of great value to..."
I wonder what the difference is between saying "an experience which is of great value to their careers later in life" with saying "an experience which is great value to their careers later in life".
I find formal documents use a lof of phrase "subject + (to be) + of + noun".

Question

Answer

We need the preposition "of" here.  This is a common construction in English, e.g., "of great importance," "of limited means," "of the highest integrity," etc.

Evden çıkmadan dil öğrenme fırsatını kaçırmayın. Deneyimli dil eğitmenlerimizden oluşan seçkimize göz atın ve ilk dersinize şimdi kaydolun!