The security boundary is difficult everywhere, here we have at least a clear baseline with decades of experience where we can slowly build from. For critical parts that don't fit on the web platform you can always fall back to a helper daemon with mutual tls or something like that. There is nothing preventing WebApps to be installed once from a good source, in fact i think this format would be a great foundation for such an electron successor. The direction of signed IWA web-bundles where the origin is a cryptographic identity seems to be a good starting point, but there is obviously still a lot to do. At the minimum we need a web of trust distribution model combined with automated scanning and completely rebuild permission and capability UX.