The millions made by cat videos are a reflection that millions of people enjoy them and advertising companies are getting lots of money out of it.
It might seem shallow and pointless but it's the human impact that really makes it valuable.
You can't lift the emotions of millions with a dozen pieces of art like the Salvator Mundi and the technical mastery of it can only be appreciated by those with an understanding of art.
The closest everyday people can get is listening to the story of DaVinci, and dreaming a little.
Maybe a unique breed of cat would be worth millions, if they existed.
Because cats are mostly fungible[0], and easily supplied, there isn't the exclusivity that would otherwise give them a high price tag.
[0] There are rare, expensive breeds. But even there there is a limit to what will pay for basically a cat.
https://en.wikipedia.org/wiki/List_of_most_expensive_paintin...
The best art isn't just a commodity or an object, it's an event with lasting cultural influence and impact.
A culture that stops making that kind of art - because "the markets" decree that cat videos generate higher short term returns - needs to ask itself whether that's really such a great metric for assessing real value.