I don't mind the effects, to be honest...
The combat looks excellent. I know, an opinion, look out.
Also, they're a sort of visual language, since the game allows such things as combo detonations, it's useful to see when an enemy is effected by ice or electricity. Buff auras on enemies also needs to be a thing for you to make tactical decisions. Being stylish is certainly part of it, but it's a mistake to assume everything is just sparkly stuff; it's relevant to communicating with the player so s/he can make informed gameplay decisions.
I support an option to tone it down, but I don't think I would. I hate reading text during gameplay, tends to break my immersion; and keeping track of the talents/powers of four party members and however many enemies are in the fight would be a major drag without distinct visual feedback. Oh, Cole just went invisible, Cassandra just challenged that specific enemy, Solas froze him, and so on. Following the action by the colours and auras is a preference I lean to.
When you pause the game and use tac-view, you want to be able to read the battlefield, not text balloons hanging off it. Therefore the effects need to last the thereabouts duration of the talent/power in question, and the visual effects also needs to be large and unmistakable, otherwise you’d have to zoom back in on everything just to figure out what’s going on.