At the time this library started the most solid open source alternative in my opinion was Oxyplot which is really good, but I had a bad time trying to make Oxyplot match my modern UI, so I decided to give me a try and start this library.
The second alternative was to pay for a charting library, sadly for a young developer is hard to buy a charting library when prices start at 1,000 USD.
So my decision was to start this library, after 3 days or so I had some charts working and I liked the results, so I shared them with the GitHub community, some people find them useful, after some months I decided to maintain this project seriously.
At the beginning LiveCharts was just animated and good looking charts, performance was not the target, but as the time passed and the library become a better alternative I decided to spend some time to improve the performance of the package.
I really believe that the Geared package should have a price to keep this library alive easier, LiveCharts.Geared is a really solid solution to some other high price alternatives we currently have, LiveCharts prices will never be high because it is maintained by me but built by everyone.
I hope LiveCharts helps you in any of your projects, and please contribute!