It all depends.
How useful is this person, does he deserve heals? Or you do more when doing dps yourselves and let the person die?
A good support should know who need heals and who can do without for a while.
A person who plays a hero that will go hard into the enemy team to do damage like a rein, genji etc and dont have self heals/armor regen. Need to get heals else they will stand in the back doing nothing or moving to health packs during group fights.
Yes utils are important but so are your team members. Loosing a 4vs6 is bad. Except when you turn around the fight with a good ability. But most of the time trying to at least keep it an even fight (players) is better.
Even on rein(main tank) and between fights, I had games were I stand between healers who just dpsing/doing poke damage while i have to first run back to a health pack to heal up so i can go attack again. Healing will give you easier ult charge then shooting at shields or hoping to do some poke damage.
Also it is all about risk and reward. A support can not take to many risks, since loosing a main healer is in most cases a certain loss. Still i see lots of baptista’s and moira’s taking very high risks going on wide solo to flank alone and get them selves killed.