There was a community-driven project for exactly this. It was hosted on http://tldr.io. There was a browser extension showing you the summary of an article when you visited it and you could contribute your own summaries. And I started creating a Windows Store app (back in the time of Windows 8.0) for browsing all TL;DRs.

But sadly, the project has been discontinued for a couple of years already. I think it lacked incentives for summary writers (for example micro payments from summary readers) and also a monetarization model for the project creators.

The code is still on GitHub: https://github.com/tldrio

I thought about contacting them to get the web service running again on some cheap AWS VM or so, but haven't done it yet.