Djoker beat Federer at RG and Fed is certainly still a member of the Top 4.
And about those 4/5 biggest events...the WTF is not necessarily worth less than the Olympics so what your saiyng is pretty arbitrary.
1) Did you read my first post of the thread? Apparently not. I said the streak of five losses began after Fed at RG. Since, other posters brought up his individual losing streaks to the top players.
2) I said 5 biggest events. WTF is the 6th biggest event this year. Ask any player - I don't think you'll find more than 2% who value WTF over Olympics.