Is funnelling a symptom of assassins being too weak?
I thought a bit about it and usually funnelling comes in two versions, protect the carry which FNC tried twice (3 supports) and just a funnel combo with standard lanes (karth+nunu fx).
Now a funnels glaring weakness is that the carry doesn't get any harder to kill and just like any other person that snowballs become a giant target, take that boss down and the enemy is out of oomph, however with assassins being unviable (in pro at least, yoloQ anything goes) there is no reliable way to take down a fed person. This mean that the rock paper scissors. Assassin>funnelling protect the AD>Assassins classic>protect the ad Funnelling>Classic(and protect AD)
With assassins out of the picture Funnelling just becomes a lot less risky since you don't even need reliable support to keep the ultra carry alive. (An example is optic vs Fox this week, only supports are the classic but that is plenty to keep the AD alive.)