What was a crypto that turned into a disappointment for you? Excluding scams/frauds

So I'm interested in learning what crypto project did you buy into that turned out to be a disappointment?

There is thousands of cryptocurrencies/tokens out there with hundreds being added at any one time. Just like trying to be a rockstar, thousands try and only a few ever succeed. It's slim that most projects return to the glory of the first ATH and bullrun.

To help cut back on the more useless mentions, I'm not talking about the long shots, or the just straight yolo buys but the ones where you legitimately brought in after looking hard at it, seeing a viable play/strategy and thought this has a chance, this one ticks all the boxes for me.

So what was it?

What made it so compelling at the start, and what do you attribute to it's failure in your eyes?

Was it a lesson to be learnt or more just particular to that crypto project?

Edit: cheers to those taking the time to give a proper explanation