Objectively you are correct. However, as the rest of my comment indicates there are important marketing and brand-value perception reasons to have a true high-end card: how many professional gamers (streamers, e-sports, extreme overclockers, etc.) who do buy this class of GPU are there playing with AMD cards vs Nvidia cards? How many (tens/hundreds of) millions of views do they collectively get playing games with Nvidia hardware? Nvidia has likely gotten millions of dollars in effectively free marketing just for having these cards.
AMD's GPU market share has been shrinking with the general gaming audience despite the fact that their mid-range cards have been very price-competitive with Nvidia's offerings during the same time period they've lacked serious competition at the high-end. While focusing on the mid-range where the highest volume of GPUs are sold is the rational market strategy it may not be a winning market strategy in the real world.
AMD's GPU market share has been shrinking with the general gaming audience despite the fact that their mid-range cards have been very price-competitive with Nvidia's offerings during the same time period they've lacked serious competition at the high-end. While focusing on the mid-range where the highest volume of GPUs are sold is the rational market strategy it may not be a winning market strategy in the real world.