That’s a comparison with ODECC vs non ODECC memory chips not DDR5 vs DDR4.
ODECC was added because they wanted to be able to use DDR5 chips which would have had unacceptably large error rates without it. In other words that improvement is before the binning process, so they are selling chips with a vastly higher innate error rate to the point where the average DDR5 stick could actually be worse than the average DDR4 chip, it’s hard to say without large scale testing from multiple manufacturers.
ODECC was added because they wanted to be able to use DDR5 chips which would have had unacceptably large error rates without it. In other words that improvement is before the binning process, so they are selling chips with a vastly higher innate error rate to the point where the average DDR5 stick could actually be worse than the average DDR4 chip, it’s hard to say without large scale testing from multiple manufacturers.