https://www.techpowerup.com/301332/nvidia-geforce-rtx-3060-ti-with-gddr6x-to-replace-standard-model-with-gddr6
 
NVIDIA recently updated its product stack with an 8 GB 128-bit GDDR6 variant of the GeForce RTX 3060 (originally 12 GB 192-bit GDDR6), and the RTX 3060 Ti with faster 19 Gbps 256-bit GDDR6X memory (originally 14 Gbps 256-bit GDDR6). We're getting to learn that the new RTX 3060 Ti GDDR6X variant is designed to replace the older GDDR6 variant. NVIDIA's add-in card (AIC) partners are reportedly winding down orders of the original RTX 3060 Ti in favor of the newer GDDR6X variant. Perhaps the most striking aspect of the GDDR6X variant isn't that its memory bandwidth is 35% higher than that of the original RTX 3060 Ti; but that it sells at the same price.

The new GeForce RTX 3060 Ti GDDR6X is based on the 8 nm "GA104" silicon, and has the same core-configuration as the original RTX 3060 Ti, with 4,864 CUDA cores, 152 Tensor cores, 38 RT cores, 152 TMUs, and 80 ROPs; the same GPU boost frequency of 1665 MHz, and interestingly, the same typical board power of 200 W. What's changed is the switch to 19 Gbps GDDR6X memory compared to the original's 14 Gbps GDDR6, which results in a memory bandwidth of 608 GB/s, compared to the original's 448 GB/s.
 
It makes sense to discontinue the older SKU in my personal opinion.