1)Heal is just a nice addition to dispel mass hearts and boss's buffs in this content and -20% attack cframe is very nice debuff too. If you don't need it - you are highly above average player's power level.
2)if you arent strong enough... it's about 90+% players. if you don't have 3+ ssr hime of chosen element and additionaly very good grid and no good ssr heal of chosen element, or you're even stronger and can not to use heal at all, or there are debuffs/buffs to dispel - there is nothing wrong to use Sol in every team, she have no elemental disadvantage at least as light hime.