https://wccftech.com/report-nvidia-geforce-rtx-30-gpus-to-be-in-short-supply-until-2021/

One of the primary reasons that NVIDIA decided to go with the Samsung 8nm process was because the company would allow them to overcome the capacity constraints inherent in buying from TSMC. Unfortunately for gamers, however, Anthony over at Tweak Town is reporting that stock is going to be scarce until the end of the year and if you want in on the Ampere GPU craze before then, you better preorder.

The reason that Anthony's sources gave was that NVIDIA is unsure of the maximum yield of Samsung's process and considering the clear performance advantage they have over basically everything, they want to (voluntarily) reduce the numbers of wafers produced till yield can be maximized at Samsung's end. This is a very sensible business decision but could ultimately end up jacking up prices for the RTX 30 series way above the MSRP as people pre-order the limited supply and then resell at much higher rates to indulge in some profit-taking.