New Keystones don't tailor to all roles.

While some of the new keystones and runes are fresh innovative ideas, they are quite lacking in the diversity of roles they can be used in. Predominately the roles of mage and healer.

Most mages only have the option to use Comet, Aery or Electrocute. You can shorten it by saying mages without solid CC or even a slow can't effectively use comet to its full potential. Electrocute cant be used by many mages that have trouble getting off 3 spells which is a pretty decent amount. Which leaves Aery which was clearly designed to be a poke support keystone, but has been abused by just about every roles causing it to be nerfed.

Healers on the other hand have no good keystones that help them heal. You can either improve your cc or your already small damage output.

I come actual season we can see a change in some of the weaker less used keystones in favor of having variety. Lets be real, Phase Rush is good on maybe like 6 Champions, I haven't actually seen anyone use Glacial Augment or Unsealed Spell Book, and with the other options in the Precision category, Fleet Footwork seems irrelevant.