Short answer: there is a massive supply vs. demand imbalance.
Longer answer: It's unrealistic to regurgitate thousands and thousands of news articles written in the past eleven months about this. There are probably 10-15 major factors that have contributed to this.
Start by reading this short April 2021 article by Brad Chacos from PC World:
You can't find a graphics card for anywhere near suggested pricing right now. Why? It's complicated. We explain.
www.pcworld.com
Several points: there is no single factor that caused today's situation. Some dimwitted people might point their fingers at a specific factor -- like cryptocurrency miners -- but all of their logic falls apart with the most superficial analysis. That's why Chacos says it's complicated.
Apparently you have been living under a rock since the semiconductor shortage has affected many other industries such as automobile manufacturing (including manufacturing line shutdowns due to chip shortages). If you had a retirement account or even just read mainstream business news, this would not be a surprise to you because it affects companies like Ford, GM, and Toyota.
For supply, the primary issues are insufficient capacity and materials shortages. There aren't even foundries either on the latest nodes or the older nodes. That's why it's not just GPUs that are hard to get. ICs for automobile and industrial applications -- which aren't on the latest nodes -- are also affected. The materials shortages are widespread. It's not just substrate materials for silicon wafers. It's pretty much everything: metals, plastic, etc. Have you seen the price of lumber in the past year?
From a GPU perspective for demand, it was a perfect storm. The launch of two new videogame console lines (Xbox Series X|S and PlayStation 5) combined with Ampere (Nvidia) and RDNA2 (AMD) graphics card releases -- all at the same time -- put extra demand on the newest nodes and thus Samsung and TSMC's foundry capacity. Both AMD and Nvidia have prioritized chip deliveries to their major customers: Microsoft/Xbox, Sony Interactive Entertainment, and major PC builders (Dell, HP, Lenovo, etc.). That's why a prebuilt PC is currently the easiest way to obtain one of the latest GPUs.
Even the local mom-and-pop PC shops have top tier AIB graphics cards in their locked glass display cases. Customers need to buy a bunch of other components at the same time or order a custom built PC to get one of those desirable cards.
Don't listen to anyone who blames crypto miners. GPUs prices did not plummet when the crypto prices plummeted. Also as you will note, graphics cards that are useless for mining (like the Pulse RX 550 2GB that I picked up in September 2020 for $65) have also skyrocketed in pricing. It's worth pointing out that bitcoin is mined on custom ASICs -- not GPUs. Crypto pricing is almost exclusively determined by buyers and sellers: not by mining activity or total hashrate.
When will this end? Sorry, my crystal ball is in the shop. However all of the major industry leaders (AMD's Dr. Su, Nvidia's Huang, Intel's Gelsinger) don't expect the situation to get any better until late 2022 at the earliest. No one here will give you any better estimate. One thing for certain: no one will be buying graphics cards below MSRP for the next couple of years.
Another thing for sure, supply constraints -- particularly manufacturing capacity -- will not be solved overnight. A new foundry costs billions of dollars and years to build; the semiconductor industry is notoriously loathe to start new foundries if there's any risk of standing idle. That's a big capital investment not generating revenue. Twenty years ago there were something like 20-25 semiconductor manufacturers. Now there are essentially three: Intel, Samsung, and TSMC.
Supply chain issues aren't exclusive to the graphics card business. They are prevalent pretty much in every industry on this planet. Compare your grocery bill today from a year ago.
There are other factors. Sure, COVID-19 but again it's not the only factor. Climate change affects a lot of supply; in the case of semiconductor manufacturing, the drought in Taiwan (where many of the foundries are) has resulted in reduced availability of water which is a major resource necessary for chip production. Again it's complicated and the factors go far beyond Chacos's superficial analysis.
For graphics card availability, the biggest issue are the people who are willing to pay scalper prices for GPUs. They are essentially the main cause of today's prices.
However, this is a free market economy, sellers will price items at what buyers will pay. The prices will come down when buyers stop paying exorbitant prices. This isn't exclusive to the PC graphics card business. This is pretty much the same for anything: heads of lettuce, sex toys, real estate, sneakers, Class B shares of Berkshire-Hathaway, whatever.
Patient buyers will have an easier load on their wallets. Impatient buyers will get reamed.