It’s been noted in Marvel Comics (most notably by Adam Warlock in the Infinity Gauntlet event) that Thanos has a tendency to subconsciously self-sabotage when he has that level of omnipotence.

Adam Warlock gained massive popularity during his time in Jim Starlin's Infinity Gauntlet in 1991, where he went on to help take down the fury of the Mad Titan, Thanos. As the wielder of the Soul ...