As mentioned in the show,
goal of gaining a great deal of power was, at least nominally, motivated by a desire to stop Thanos:
QOVAS: Thanos and his forces have begun an assault on your world, even as we speak.
TALBOT: Well, then, I've got to get down there with the Avengers and take on this Thanos.
QOVAS: Thanos' strength is unrivaled. You will lose even with your powerful friends fighting alongside you. Though perhaps there might still be a way.
Agents of S.H.I.E.L.D, "The One Who Will Save Us All"
He didn't succeed in getting all of the gravitonium, of course, but that was his goal.
Talbot had a dramatically inflated notion of his own powers, so he can't be trusted, but Qovas was very familiar with gravitonium and Thanos, enough to know that Talbot without the additional gravitonium stood no chance (and, really, didn't have any reason to want to make such an unstable individual more powerful unless it would benefit him in some way). And in the MCU, even Thanos with all the stones isn't unstoppable, as we saw
with Thor, and to some extent with Wanda.
So, was this a realistic plan, or was Qovas mistaken or being deceptive? Would all the gravitonium have given Talbot a chance against Thanos? In particular, has anyone associated with the show commented on this?