One of the most successful partnerships that have been formed between bowed strings instrumentalists and pianists, was for sure, Mstislav Rostropovich with Benjamin Britten. In the early 60s, Rostropovich already established with great reputation, as an obsessive commissioner of new works, asked to Britten to write him a piece for cello. The composer consented, and in 1962 produced the Cello Sonata, Op. 65. This became Britten's first of five major works written for Rostropovich over the course of the 60s - the others being the Cello Symphony and the Three Suites for Solo Cello.
Absolutely. Two superb and empathetic musicians. It must have wounded Rostropovich to the hear when the vindictive Soviet Union prevented his wife from singing at the premiere of The War Requiem.
The fact is the cello's repertoire was and is considerably smaller than either the piano or violin comparatively speaking. Rostropovich single handly expanded that number commissioning & premiering several hundred works far more than any other cellist of the time. Among those works, Britten's are held as masterworks for the instrument. You're under no obligation to enjoy the work, that's your option. But to state that either Britten or Rostropovich wasted their energies because you don't happen to enjoy the work seems a bit foolish. Furthermore, Slava performed and recorded almost all significant works written for the instrument, passed on his knowledge to a number of talented younger artists, and was an active conductor. So what is it in your humble estimation that he should have been doing, if not supporting one of the greatest composers of the century?