Are shealding/healing supports better?

As bot lane main I see that healing/shielding supoorts are much better than other picks. I mained Thresh and sometimes you make good plays but you don't bring that much,sometimes if your adc is bad you can't save him from sime situations instead of havin lantern. But I started palyin Sona,Soraka,Janna and Karma now and Iwin mire games now as support. I bring much more to team saving teammates. I kinda see that as a support you are more usefull when saving than securing kills. As Thresh you may hit a hook than go in send lantern and you both die. With heal/shield supports you din't make that risky plays. Sometimes as Janna I even carry I save my 1000 gold worth adc from instant death. Even when I play adc I see those champs as supports better today I had Soraka supp and after every trade she healed me and herself, while Varus and Morgana where low. What are your toughts what supports are better for the team high damage ,healers/shielders, takns?[sona-playing]