There's Electrino, which provides the Electron api but runs whatever your OS's built-in rendering engine is: https://github.com/pojala/electrino Still in development and relatively limited, but the idea's there!
There's also Sciter, which is supposedly very mature (even more so than Electron), but as it's closed source and released under a mixed licence (there are free and commercial versions), it's not got much traction outside of commercial apps:
OMG, I had never seen Sciter before, All I thought is a lie, ESET, Norton, Avast all were using HTML even before electron exist. I always thought theirs software was made by hand using native APIs and frameworks.
https://sciter.com/