I've been watching this take off over the last week and a half and yeah, it really seems like the next big thing.
On one hand, the digital (NFT) Garbage Pail Kids cards aren't "real" in the physical sense -- you can't hold them in your hand show them to your friends IRL. However, from the standpoint of the collector, they should be every bit as real -- they exist to a certain extent and are quantified on the blockchain. So long as the blockchain runs, they "exist."
What does a collector do with their cards anyway? They don't stare at them all day. Most of the time they just sit there, occasionally being showcased or traded. WAX and Topps make both of those easy to do. And of course there are benefits to them being digital rather than physical: they won't get burned up in a fire, they won't decay, you can't spill coffee on them.
I know Topps has plans to launch more card series on WAX in the future -- hoping the idea catches on with the physical card collectors.