Yes, but QLC has much higher density.

I think it's the higher density that makes it better for cold storage, which generally has infrequent access, and more reads than writes.

Hence the QLC's endurance being "sufficient for cold storage".

Cold storage normally doesn't have frequent writes or frequent reads.

Ssd for cold storage seems like an odd choice in itself. If that’s genuinely done due to availability then we really are in for a wild ride

I believe "cold storage" in this parlance is more like "read-oriented" rather than being accessed once in three years.

I think it is solidigm that has started to argue that with a 128 TB QLC drive constant writes at the maximum write rate will hit the drive’s endurance limit at about 4.6 years. The perf/TB of these drives is better than HDDs. The cost per TB when you factor in server count, switches, power, etc., is argued to favor huge QLC drives too.

In short: Aggressive overprovisioning.

Enterprise SSDs are not expensive only because they have better flash chips, but they have much more of them.

A top of the line write oriented SSD comes with 4-7x more capacity than what it says on the tin, but that extra capacity is used for cell replacement rather than capacity itself.

Mixed use comes with 2-4x overprovisioning, and read oriented is around 2x IIRC.

I find these numbers to be way outside of what I have heard of. I would be surprised if you could give an example that comes with even 1.5x capacity. (4TB capacity, 6TB actual flash on chips, for example.)

Overprovisioning is much less aggressive than this in practice. A read-oriented SSD with 15.36 TB of storage typically has 16.384 TiB of flash. The same hardware can be used to implement a 12.8 TB mixed-use SSD (3 DWPD or more).