There's masses of value-add if you are plugged into the Apple ecosystem as it will act as a second screen for any other Apple device (like an iMac), you can handoff to it (so stop whatever it is you're doing on the computer and carry on while you walk around the house) and it can act as a HomeKit hub for home automation.
Since your predominant use sounds like you just want a small format laptop without a keyboard but with a touchscreen, I'd say no ...
Remind me, you've already got a Chromebook right? I'd say a (cheaper) Android tablet would be both more familiar and more use. Even without the rest of the Apple ecosystem around you, the iPad is a very excellent tablet but you're likely to underuse it significantly and/or get frustrated that the Apple apps will behave in ways that you're not used to.
Just checking ... email? Webmail or via an app? Not that it matters, just that the "everything in the browser" approach from ChromeOS is really sound for most people. I think you'd be a lot more at home with the Lenovo Duet.
If you were to go back towards a Microsoft machine, Surface is very nice to use and Windows 10 is quite mature now - you get the Edge browser (which is based on Chromium, the open source behind Chrome) and could easily do everything there. Windows is being left behind on the app front (nobody credible does old-style Win32 applications, it's iOS and Android for literally everything you buy now that you'd want to integrate and interface with from your portable computer), where a ChromeOS tablet will do the Android app (albeit from satisfactory to badly, in my experience of ChromeOS). If you were spending Surface money, I'd say go for an iPad instead.
Again, I think you'd be a lot more at home with the Lenovo Duet.
HTH.