Is Dissipation really that bad?

[Jerichai]

when do you use 20% magic damage reduction? why is largess adlo a waste of combo cooldowns? isn't that why you pop sacred soil asylum and collective uc. during raid busters? when do you use your illum and covenant?

You're burning cool downs to set up a large amount of healing while simultaneously limiting the amount of damage your group will be taking. Do you really not see how that might be wasteful, especially factoring in content design and the probable existence of a second healer?