You mention Juan Jesus and Frog, who played a lot in 2014-2015 and we had a +11 goal difference in 8th place. Also D'ambrosio was already at Inter by that time.
It's our attack (Icardi, Palacio, Shaqiri, Podolski) together with some of our midfield players (Kovačić, Hernanes) that did enough, it wasn't just Handa.
That seasons we conceded 48 goals, which is the same as Atalanta this season. This season we conceded 42 goals and our defence is a lot better. So I don't think we had such a bad team that it's a wonder why we didn't fall into Serie B.
After that we added Telles, Miranda and Murillo, so our defence was slowly getting better with almost every season. So I'm not going to talk about those seasons, as the "it's only Handa that carried us" just doesn't apply.
Handa's first season he entered an aged group, but full of champions. In attack we still had Milito (who sadly got injured, but he still scored 9 goals <3), Cassano, Palacio.
Cambiasso was still only 32, but overall all the other midfielders were more miss than hit - Kova too young, Guarin good, but not great, Kuzma lol, Joel Obi lol, Ricky Alvarez

, old Stanković,...
The defence was also meh, also had Schelotto

.
This is probably the most impressive season for Handa, even tho we finished 9th. The whole squad was mostly old or mostly shit.
And the next season (2013-2014) our squad got a little bit better and Handa was at his best. That's hist best season for us and followed by his 1st season, 1st Spalletti season and second Conte season his best here.
So what I conclude, he had 2 seasons when he was basically a shot-stopping god for us, but still had faults in his game. But still, those two seasons are the most talked about, so maybe he was the thin line that separated us from Serie B. But after that, the team got slowly better and I don't believe he was one of the best ever in Serie A. Maybe he didn't get to show it because the defence got better
