I do think 5e benefits less from an E6 than 3.5 did, but I still think the concept is solid. It really comes down to the fact that once you hit 4th level spells (and even more so 5th level spells)...the gameplay does start to shift.
Divination as a ritual, banishment and wall of force as 1 shot monster "kills", the raw physical power of polymorph or animate objects....the game does shift in a way that a DM has to adapt to keep a proper game flow.
I will repeat, doesn't mean its a bad thing, but for those who aren't looking for the gameplay to shift as dramatically, and E6 concept can work very well.