It was rough a few years ago, but nowadays it's pretty nice. TI rebuilt their Code Composer Studio using Theia so it does have some larger users. It has LSP support and the same Monaco editor backend - which is all I need.
It's VSCode-with-an-Eclipse-feel to it - which might or might not be your cup of tea, but it's an alternative.
* https://code.visualstudio.com/Docs/languages/markdown#_inser...
I don’t mind project being done and in maintenance mode. But I am not investing my time into starting using it.
Getting started page has screenshots broken on AWS.
At some point in time, I'd like to take the time to invest building a custom version of the extension to bump dependencies to access more modern support for plantuml/mermaid diagrams.