SCH during the Stormblood expansion was actually a great way to handle a healer who could also put up DPS. Most of SCH's damage skills place a DOT meaning they didn't have to decide between casting Miasma II, Shadow Flare, etc and accidentally letting the tank die because they only had to cast those skills once every 15-30 seconds. This allowed them to maintain both healing and DPS uptime and it made the class one of the best, if not THE best, healer during the Stormblood expansion as well as one of the best healing classes in any MMO.
The changes ShB brought absolutely destroyed any and all fun I had as a healer and single-handedly made me dropped healing as my main role. Being able to quickly spread your 2 main DOTs was also a huge quality of life over now having to cast it on each and every mob in a pull in a meta dominated by wall-to-wall pulls, which AST and WHM would still have to do even if they didn't gut SCH's skills. You can no longer mitigate damage with the slowing effect of Shadow Flare, their only skill had offensive and defensive benefit (ie. Assize, Stellar Explosion). WHM was meh before ShB and AST provided way more utility since it could do more than just give damage and to just 1 person at a time.
tl;dr - Before ShB, healers had way more to do outside of just healing people and that's why they were fun - yet ShB removed most offensive tools healers had to focus on this heal-meta is both incredibly dull and largely unhelpful as most end-game players optimize around mitigating damage to maintain uptime instead of just healing. Yet we still get changes like the Energy Drain nerf to punish people who want to try and break away from the mind-numbingly boring heal meta.
Healers feel worse now than any other expansion. You are just there to keep the party alive and otherwise contribute next to nothing the in most fights towards endgame. As long as people want to clear stuff quickly and repeatedly, the DPS meta is always going to be the preferred player choice outside of doing specific niche farms. Nowadays, I just play healer because I'm often in queues where there are *literally no healers* due to how most of everyone just doesn't find them fun to play anymore.
But none of that
None of it
Was as bad as losing Protect.