The reason why NFT artwork is worth millions isn't just for a speculative market so another chump will buy it from you at a higher price, but it also has another value. Like all artwork it is used for tax avoidance. The high price of NFTs allows a wealthy elite to squirrel away millions to accrue value without being taxed. They are more handy than a real piece of artwork or some expensive property in London because a digital image isn't vulnerable to physical damage or maintenance costs. It's obvious why this shit is exploding.
The only people making money off of them are the people creating them, and the cost to "mint" them is so low that basically anyone with some Ethereum can put some out there to see if anyone bites.