I'm running 64 GB ECC with a Ryzen system. As it turns out, memory in general was just exorbitantly expensive in the recent past, so the ECC premium wasn't all that much. On the flip side, I don't do PC gaming so having faster memory didn't really matter much; current ECC was already faster than the 5 year old system I was upgrading from.

For me, the reason to go ECC was just to prevent silent file corruption. With 64 GB, the math is in favor of me seeing bit flips. Moreover, I tend to put my machine to sleep, rather than shut it off, which also increases the likelihood of memory errors. I wouldn't say I have a highly specialized workload outside of the occasional VM, consisting of large files, for development. A lot of it is I just didn't want to deal with silent corruption of family photos & videos, even if the underlying file formats are pretty resilient.

Personally, I think the situation should be flipped. Everyone should run with ECC these days and only run without for specialized environments like gaming where you want to squeeze out every FPS you can. Faster memory isn't going to matter for most situations.

Protection against memory errors, I don't have exact odds of such errors, but certainly not negligible and with faster memory and capacities - those odds only increase. Many such errors will go unnoticed and the impact for most will be unknown, but can equally be very impacting. Hence today it is only critical systems that have such use, as can justify the extra cost.

But for everything else, it's a scale of needs, sure the low-end would be a gaming console or graphics memory, but if that gap gets smaller, uptake and usage will scale as that advantage becomes cost effective at various consumer levels.

But having the option of choice, is and always been a huge plus for any consumer - AMD makes that choice far more accessible than Intel. Though I do see a mobile phone maker going ECC as the turning point in uptake and making that price gap more palatable in the end.

If you value stability and no file corruption, you'll go for ECC.

If you use it just for media consumption and playing games, anything goes.

A good power supply and ECC RAM make a very stable PC.

If you have ever had a corrupt file on your hard disk, ECC memory can help prevent that. Usually data corruption happens in memory (and then is saved to disk).

In short, stability. If the performance hit is low double digits, that may not even be noticeable for many use cases.

Reliability.

Whether one cares about that is one's own tradeoff.