I "use" Chrome on my iOS/iPadOS devices periodically. I use it for the integration with Google services, the shared state with Chrome on my other devices -- bookmarks, currently open pages, passwords, etc. I jump between devices and this integration is critical. This is mostly between my iOS and my Windows existence.

I use Safari in a similar way, albeit mostly between my iOS and macOS existence.

The number of times I've missed a Chrome engine feature is somewhere approximating zero.

So saying "most of their value" seems pretty specious. If Chrome were faster, used less power, or had some value proposition rather than integration, sure, but it isn't. Here's a fun hottake - Chrome forced to use webkit on iOS is almost certainly better than Chrome would be if it used Google's own engine.

"because they do not implement crucial features in WebKit, like push notification"

There is always something that becomes the critical missing ingredient. Yet uptake of web apps on Android and the desktop is somewhere in the proximity of non-existent (but always explained away by shaking one's fist at Apple). The suite of features in web apps has grown spectacularly, and now encompasses high performance graphics, a massive VM, game controllers, gyroscopes and cameras and microphones, but there is always just one more thing that Apple is always to blame for.

This is another futile thread that is going to be brigaded by the anti-Apple crew, so please enjoy downvoting to try to assuage whatever hangups you have.