M+ and Specs Question

[Castle]

Hello guys,

New poster here, let me dive straight into my question.

Is Fire the undoubted best for M+, add cleave type situations or is it possible to achieve similar numbers with Frost and Arcane?

If so, what is it about Fire that just makes it so much better, is it just ignite?

[Katsumi]

Welcome!

All three specs are perfectly viable in M+ right now, as could be seen nicely during the invitational.