It's all subjective, but I haven't grown bored of healers in PF and almost always have to adjust my gameplay around my co-healer or the parties gameplay overall. It is never a dull moment on reclears even considering the scriptability of the damage and mechs. I have had more satisfying saving the raid moments on PF then ever in a static, especially when a co-healer goes down on a big mech. That happens way more often on PF and I stand by the optimal gameplay experience for current FFXIV healers is in PF, not in statics. You can't really use your full toolkit in a static. While that is a problem, it is also a separate one with a separate solution.
If the goal is to increase Healer supply in PF, the solution is to reduce responsibility (including a more lenient gameplay loop) of the role so people would be enticed to the additional responsibility. Separate from any other enticing solutions SE could implement.
If the goal is to make Healers "fun" or "fixing" them, both of which are also subjective in their suggestions, then the best path that everyone can deal with is to redesign all of the jobs from the ground up and how encounters engage with the healer (and other) roles.
Even still for either solution, you will still absolutely have a problem getting people to play the role as the AVERAGE MMO player tends to play a DPS role in literally any MMO. No game has found a perfect solution for this but SE does have some options like Job-in-need guaranteed drops or specialized role tome acquisition bonuses they can implement to soften the blow.
TB's happening less, does not equate to difficulty in PF. In fact, TB's on average don't matter because they either don't hit hard enough where a healer has to pre shield them (despite tank mits), or if they do hit hard enough, the occurrence of said TB's is so spread out that the tanks can just cheese them with invulns. Something more to PF determining dificulty is like the AoE's that are followed with hard ticking DoTs, which require more of a follow-up of GCD heals on average or overlapping body check/ doom mechs that require re-topping players. The problem is, when this happens in a raid tier, the PF supply of healers goes down not up.