As someone who switched to healer main for raiding this expansion, and as a WHM, I really have to disagree with most of this? Lilies are still pretty terrible and add very little to the job; CDR on a job with abilities planned for certain moments rather than used-on-cooldown ends up being a rather wasted bonus at best and usually a case of trading GCDs for no net gain in total oGCDs used in a fight. The change to Plenary was a pretty big deal as it made the skill not entirely useless. Benison is a pretty nice skill but since healing design in the game has always been to minimize GCDs ever spent on ST healing, it's still in that kind of awkward spot to enable it.
I've never cared about what people said about lilies from a design perspective. They work. Even when they didn't work as intuitively as they should have,
they still worked. And now that they are a guaranteed bonus, they worked even better. Other classes have had similar fumbles with their mechanics, Black Mage in particular has consistently been an aggravating class to main. Lilies are a passive CDR that you can either deliberately or passively use. They felt a bit clunky to prepare for back when lilies were RNG, but even back when we could only assume the mechanic's effectiveness, there still was no real reason why I would have expected the class to underperform considering the rest of their skills.
Then there was all the bitching about optimal healer play, and that's where I really start laughing. Because 95% of your raiding experience in any game is going to be very far from optimal. People are gonna screw up mechanics, your healing partner is going to be bad, wipe fatigue sets in, DPS are going to stand in explosions, tanks will miss mitigation, people will be undergeared, ect ect. Conversation about WHM's supposed focus on healing with no supplemental raid damage when "FFXIV isn't even that hard" always felt like it was just assuming that everyone involved was going to be in a raid party full of people who are just amazing at the game. That is NEVER the case, in ANY team-based game, so it's silly to start the conversation there.
So even if their worth is limited from a purely "we're so good at this we can speedrun it" position, it's never going to play out that way in reality. FFXIV has just never been that kind of game where those differences are significant enough to really complain about...unless the class was just SO gimped that you couldn't help but notice, like 3.0 Launch Bard. And WHM has not been in that position in 4.0.