Answer: Part of the issue may simply be money
According to AdImpact, a lot less money was spent in support of Barrow than of Pinson.
But I'm actually struck by how little money was spent in this race at all! Just over 3 million dollars was spent in 2024 in support of either candidate, which is far less than we usually see for a high profile, competitive statewide election. This may have just flown under voters' radar in general, and having Pinson marked as the incumbent on the ballot may have also been enough to put him over the top.
—Mary Radcliffe, 538