If you don’t like M+ much, you’re totally fine to play holy next tier.
It’s better than it is currently in M+ by a decent chunk due to the mana changes and having possibly the best healer tier set in Oracle. It can CURRENTLY do all your 12s just fine, it’s gonna be easier to do that next tier. So unless you’re climbing for title (why would you if you don’t like M+?) just play holy.
It’s significantly better in raid, too where both tier sets are very strong.