There are NFTs and then there are NFT collectibles.
An NFT, or a Non-Fungible Token, is a breakthrough innovation in verifiable ownership. Verifiable ownership is a critical and fundamental component of human society, be it ownership of a property, an idea, an identity, etc.
NFT collectibles are an application of NFT technology, and people use it to prove ownership of digital assets that they acquire.
Why? People are always looking for new things to collect and take pride in owning. Now they can collect virtual (digital) things and prove you own them.
People love to collect — watches, art, tulips, etc. Different collectibles have their season in the spotlight, but in every case, collectors are driven by pride in ownership of scarce artifacts.
More often than not, the production value (eg: the cost of production) of the collectible is significantly less then its trade value. We can all agree they that the production value of a single baseball card (or jpeg) is not thousands (or millions) of dollars.
Many collectibles go through bubbles, like tulips and beanie babies; others have more longevity, like fine art or wine.
Historically, people have collected physical collectibles — real world things you can interact with by physical touch. Today, much of our life is lived online, in a digital reality that we cannot touch, but can interact with, through a screen. This other, engaging reality presents an opportunity for a new type of thing to collect. Digital things.
Now that you can prove ownership of these digital things (via NFTs), collecting them just got a lot more interesting, and profitable.
The digital collectible bubble may burst like tulipmania or stick around like fine wine, but I believe the underlying NFT technology (Non Fungible Tokens) is going to be around for the rest of our digital lives.