As it’s fitting here, I’d like to link my idea for implementing the changes suggested by David Kim, and retaining the good from D2: “Effect & Focus” - Runes, Power Imbues & Sockets: Mechanic suggestion
In short:
I suggest changing the rune mechanic from “Trigger & Effect” to “Effect & Focus”
This will make effects always usable.
While at it, change the “runes” in d4 to be “Jewels” (Or “Charms”).
So we have Effect Jewels and Focus Jewels.
This frees runes to be the Consumable items mentioned in blog post - “consuming” a rune would be etching it to the weapon.
And now runes can also be merged to construct more complex runes (Like in d2, but actually very different).