Just to emphasize: Promising cryptos. Thus excluding any scamming projects like Bitconnect, OneCoin or any of the Bitcoin Diamond/Gold/Platinum or whatever variant. That segment would need a top 30.000 list.
No this is solely about projects that are not necessarily deemed a scam, or at least certainly not started out as one because they genuinely did deliver. It's just that what they delivered was either faulty, failing or like that lazy university group member at first very sincere in the starting weeks, and then started slacking off and hoped the others would not notice.
So starting at number 3: Terra Luna
Was this a scam from the get-go? I don't think so. Was it doomed to fail from the get-go? Yes. Could you have known? Yes. Why didn't thousands of Luna believers know then? Because people don't DYOR or the research they do leads them to Youtube bros who got paid by projects like Luna to push their 🐎 💩 onto inexperienced newcomers.
At its height in April 2022 Luna was sitting at 115 Euros. Today, well:

Number 2: Lisk
I must confess I'm not 100% sure what happened on this one, but it was once a +30 Euro coin, holding steadily in the top 10. Now barely holding on to stay above a penny and even after 10 years shut down its own chain and effectively became a token on Ethereum.

Quick research cites continuous changing strategies was the main cause which led to an eventual loss of trust and interest by its hodlers after many disappointing developments and price action.
I think the undisputed number 1: EOS
Once in the top 5 and hyped as one of the most advanced blockchains and sophisticated multi-use case coins. Now not even existing as neither its original name nor core competence.
Even though I myself never got aboard the EOS spaceship, just the sheer promise and dedicated hodler base EOS had really made it a force to be reckoned with and being able to mess all that up really earns you the top spot IMO.
It rebranded as Vaulta and to be fair, compared to the other two on this list Vaulta is not doing terrible in the ranking as they are still in the top 200.
But let's get real here, even before the rebranding to Vaulta in 2025 EOS was continuously going down and reaching new ATLs for 2 years straight. Not much has changed after they became Vaulta:
