Eclipse Theia isn't classic Eclipse. It's basically a remake (not a fork) of VS Code, designed to be backwards compatible with VSC extensions. They even have their own plugin registry at https://open-vsx.org/ to avoid Microsoft's lock-in strategy that plagues forks like VSCodium.
The only Jetbrains product I've used is CLion, and I didn't like it because of how bloated it was. My PC fans would kick in every time I launched it, and none of the refactoring/auto-complete features were good enough to convince me to switch from Sublime Text + LSP plugin. At the same time, my work has forced me to become a build systems expert, so I have no problems having to set up everything myself. Project templates in Jetbrains IDEs may be a hard requirement for some, which I totally understand.
CouchDB (a no-sql db, but whatever) automatically provides a REST API that's designed to be exposed directly to clients. It even implements its own client-facing authentication system. "queries" are configured in advance from the admin side, and clients just pull the results, allowing for very efficient caching. Basically, if you RTFM enough to get a couchdb instance running, you have 90%-100% of your backend complete. You could create an entire scalable full-stack app using only client-side code... and if you're clever with HTMX, you might even be able to do it without writing any javascript at all! (I tried once, but failed because I'm not that clever, but it's definitely probably possible)
So TL;DR: I like couchdb, and the idea of exposing your database directly to users isn't unprecedented. I wonder if there are any SQL databases that offer a similar thing?