DDR5 contains two forms of ECC. The first is standard ECC which is used to correct for bit flips in transmission. The second on-die ECC is used to correct bit flips on the die, hence the name. The world has already accepted that standard ECC on high speed interfaces is a good idea, so why would on-die ECC be a bad idea? Yes, they correct different error types, but they both attempt to correct corrupted bits and the do so in a mathematically similar way.
All that said, there are still ECC (has an ECC memory) and no-ECC dimms for DDR5. So if the on-die ECC is concerning for anyone, they can still get a DIMM with a separate ECC memory. But the ECC happening at the interface between the DIMM and the CPU will still exist always and you will have to trust it.
All that said, there are still ECC (has an ECC memory) and no-ECC dimms for DDR5. So if the on-die ECC is concerning for anyone, they can still get a DIMM with a separate ECC memory. But the ECC happening at the interface between the DIMM and the CPU will still exist always and you will have to trust it.