It's intended. Arcanist starts off with physick and then becomes either a scholar (healer) or a summoner (dps). It scales mostly off the mind stat which healers can stack but dps cannot, although a relatively small contribution is made by weapon damage and substats.

It's more useful at low levels where it can save a situation if the healer can't and it's also used by scholars, although not very often. A scholar is more likely to use one of their off-globals or an adlo unless they have used all of these up but that is rare.