https://github.com/pojala/electrino is electron alternative that uses the system's own web browser engine.
I have a proof of concept already, but it's not cross-platform so that's a major downside, and I don't think many people need the combination of (1) Mac-only, (2) lightweight, (3) using JS for the core logic, (4) using web views for the GUI. I just don't think there's a market for that.
https://github.com/zserge/webview
https://github.com/Boscop/web-view
and so on