At first it was as simple as cloning Bitcoin, making a few parameter tweaks and pumping the resulting shitcoin until enough greater fools bought in. That worked for a while.
Now there's a newer generation of token systems that claim to represent a technical leap ahead of first-generation blockchains and promise to be the future of payments and/or smart contracts. They all have a white paper that looks legit, and the really convincing ones have a published paper. I read a lot of them and categorized almost all of them as follows:
1. Incomprehensible BS dressed up as academic research.
2. Uses recent or novel cryptography, but states assumptions that won't hold in the real world.
3. Uses recent or novel cryptography, but doesn't have significantly better properties than BTC or ETH.
4. Basically the same scaling trick as ETH2 (sharding) achieved in a slightly different way.
5. Centralized design, therefore someone out there can take your money without compromising the system.
On top of all that, you've got well-capitalized institutions who get to play in a $1.6T unregulated market full of dumb retail investors mostly looking to speculate, in cahoots with the exchanges, whose valuations depend solely on bringing the hogs to slaughter in increasing numbers.
SEC should be all over this but appears to be sleeping at the wheel.