The OP linked the data. Go read it. According to it in 2024, FPI was “correct” 72% of the time, not 48% like you say.
For reference, 72% is pretty solid and ranked 9th.
It was correct *against the spread* 52.8% of the time, which is remarkably GOOD (2nd best of the tracked metrics).
The 48% number may be coming from 2023 where ESPN FPI ranked 48.3% against the spread, which was 37th on the tracker. Not great, but not enough to blow it up. It was still correct 73% of the time overall.
The data was linked right there for you.