How can Safari 12.1 impact mobile apps?
Apple does not do anything to stop mobile apps tracking even with the app store review and the ability to scan them both on submission and as they're running in the OS. Mobile apps are 90% of the source of adfraud and privacy issues on iOS.
Meanwhile Mobile Safari (even without ITP) has caused numerous problems with apps trying to offer webviews for content while trying to keep users signed in. There are numerous effective improvements to be made instead of messing with cookies.
After discovering mitmproxy, I checked out various apps on my Macbook. Found plenty that at least phoned home to Google Analytics on boot. Some even phoned on every action/keypress.
Not sure why HN has such a hard-on for native/mobile apps. You get performance at the expense of basically everything else. There's no dev toolbar. No extension system. No customization. No uBlock. You take it all or nothing. And you need intrusive tools like mitmproxy or Little Snitch just to get insight into their network traffic.
Electron apps can get rid of the browser chrome at least, but it comes with the cost of a redundant copy of Chromium for each app, which is worse than running in-browser in terms of resource consumption.
Web apps would be great if they could deliver the things mentioned in the first paragraph on top of their security/privacy benefits, but I don’t see that happening any time soon.