WKWebView, an Electron alternative on macOS/iOS
This is literally what Slack moved from years ago, because it was very problematic, let me tell you why since I'm the one who did it.* Adding new APIs was a huge pain in the ass, you had to write all of this ugly bridge code in Objective C, and the APIs ended up being super unnatural on the JS side. As a result, desktop integration wasn't done much since it felt like a "Black Magic" type thing. Writing new APIs in Electron is Just JavaScript, so you can make something much more natural.* We could literally do fuck-all for people running old versions of macOS - you can't upgrade Safari on old machines, you just Get What You Get. For awhile, every YouTube video on older macOS versions had a pink shade to it. Users write in, "This is clearly wrong!"  "Yep, but we can't fix it. Sorry."* And big spoiler - WKWebView uses _basically_ the same amount of memory give-or-take a few MBs as Chromium. It's the content that sets the memory usage bar, not the host.