Personally, I feel SEMC found a pretty good balance. If you add too many effects, hectic fights can become visually overloaded to the point where it detracts from the information you are capable of processing.
In a MOBA, being able to read the battlefield at a glance is extremely important. If it is being drowned in effects, that is getting progressively more difficult.
Not all heroes and abilities are animated equally well, but on the whole, the art department has done a respectable job.
The Rise, on the other hand, could really do with some sort of rework, as @PopcornOne mentioned.