Except when I buy a painting I can lend it to a museum and get a steady income, with NFTs you are only hoping that some bigger fool will buy your jpg, because everybody sees what you see, and a jpg is not a painting, you don't have to stand in front of it to appreciate it.
An example was the recent sale of the original picture from National Geographic 1983 issue. The "Afghan girl" is one of the most famous pics of 20th century if not the most famous.
The "original" sold for a mere 63k, that's because it doesn't give you anything more than the pic which was on the cover of NG or you have seen countless times on the internet since. Compare it to famous paintings or even a Banksy and it's a very small sum of money.
Most famous jpg sells for less than 1/10 of a mediocre painting
Also most importantly once you have taken the painting from the artist hands you are in power. With NFTs the artist needing money can and will mint the exact same JPG undercutting all the fools who bought the previous NFT.
He will get the money and the praise (ohh distributing his work to everybody instead of select few how cool is him!!!) and you'd get a huge financial loss.