Just to share one idea that I almost took to completion and then dropped - It was a few years ago and Slack was the top collaboration suite. I had an idea for building a unified chat/messaging tool to integrate text, images, audio, video in a single collaborative tool. I used IPFS to keep the data distributed on the peer nodes (i.e., completely serverless and p2p). Microsoft Teams had just launched. I dropped the idea knowing fully well that Teams would soon surpass Slack (and sure enough they did recently).

A good thing that came out of that was I used the video part of the tool to pivot to a different product.