Unfortunately: Yes, necessarily.
For DPS, it is largely irrelevant how they do their damage, so long as the average total contribution is identical. Big bursts with long downtimes, small and sustained, dots, pets, direct or via buffs... it doesn't matter much if the end result is the same. The differences tend to become bigger in fights where things jump around a lot and the burst jobs don't really pay the downtime price for their big bursts, because the boss is invulnerable in those anyway, putting more sustained jobs who are designed to catch up with the burst in those phases at a disadvantage. But that's encounter specific and usually a wash.
For healers on the other hand, it is not irrelevant when the heal comes, because if it doesn't come at the right time in the right amount, people die. When the damage of bosses is low but steady and healing relatively weak, that's not that important - You can make a wildfire-esque healer work, where the health bars of the party would slooowly drop bit by bit during the minute downtime because the healer can't keep up and then get all the way back to full in the burst. Or, have a healing job that can simply keep up with the damage via HoTs or another via a variety of direct heals etc etc. You're still a bit more limited since buffing other people's healing is, uh... somewhat pointless outside of a raid, as you'll be the only one healing, but there's a lot more you can do.
That is a completely different paradigm for healing however. In this game, damage is huge and spiky, you cannot make up for shortcomings at point X later, because people are already dead by then. Moreover, healing is exceptionally strong in this game and the time actually spent healing thus comparatively low, which also limits what you can do with internal healing mechanics. And on the flipside, since you have that healing gimmick you need to take care of, DPS design can't be too complex on them either.
The devs have designed themselves into a bit of a corner there and I'd expect any new healing job to be either extremely homogenized, or dysfunctional in various ways until homogenized.