I think it’s both a technology and market issue.
On the technology, red phosphors may indeed be more afraid of high temperatures, just like the official max current of 3000K SFT-40 is only half of 5000K.
On the market, most throw or high lumen LEDs, primarily for sheer output, the CRI controlled at 65-70. As most people do, either observe the color close up, either observe the object far away, few people want to observe the colors in the distance in detail.
Some custom LED enthusiasts have similar ideas, like this post.
Because this LED is not for photography, So CRI is not important and we want extreme efficacy for high performance that’s why we choose 70CRI.