Sciter and Ultralight are the way to go on paper. They address many of the issues of Electron and it does it in a very portable way. Instead of embedding the world in a giant toolkit, they give to you what you want as a library, easy to interface with native code.

However they are proprietary, and this is a no go for me and many. There is no way I bind my software stack to an arbitrary unstable compiler ABI and its platforms. Nor I will bet on a toolkit that can disappear tomorrow if its only maintainer disappears or get hit by a bus.

We need something like these projects, but OSS and still I would be happy to pay for that.