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.
Also it used to be kinda heavy, but it became lighter because of Moore's law and good code management practices all over the board.
I'm planning to deploy Theia in its web based form if possible, but still didn't have the time to tinker with that one.