Clearly yes. The release of the new AMD & NVidia graphics cards, both recommending a 750W+ power supply along with shipping and manufacturing delays, also combining many people looking to build a new PC during lockdown to keep themselves busy has meant a huge shortage. It used to be a 550W PSU was sufficient for 90% of builds. Now I’d say a 650W is the minimum and for a top end gaming PC it’s 850W+ as you’ve found. There is some stock out there if you know where to look but I feel some of it is either from a lower tier brand or overpriced.