I have a similar problem, I have a hard time getting focused on a laptop. There are too many distractions, the inputs are too convenient, and it's only getting worse as more things move to the browser. I get so distracted on my laptop that I can completely forget I was working on something and now it's lost, sitting there waiting for me to return to something I don't remember working on.
For example, I never worry about rebooting my iPad for updates. Never. Any time it asks, as long as I'm not actively doing something, I let it. It's 10 minutes, I'll get up and get a cup of coffee no problem. But rebooting my laptop for updates? I have no idea what all is running in the background. I've got five Excel documents, a Powerpoint, and two Word docs I'm working on. Plus a probably an SSH connection to somewhere, plus who knows if Slack is going to come back properly or if it will make me log in again, plus I'll lose my browser sessions and have to log in again to all my work stuff, I need to manually re-establish my VPN connection, and as it all comes back from the reboot, now I have startup crap popping up on boot that I forgot about from last time. Ah shit, and now I find out this update broke some of my software so now I have to find new versions manually for that. And now I've again forgotten what I was supposed to be working on.
I have the same problem you have on a phone, it's too easy to switch between apps and be unproductive. But I've found that (for me) working on an iPad is perfect. I don't have multiple windows open, most apps are expecting to be shut down in the background so they save their state really well, minor OS updates never break app functionality and if something changes, the apps update themselves. And even switching browser tabs is just a tiny bit of a minor inconvenience that I'd rather finish what I'm working on and then get distracted.
Right now on my laptop I have five windows visible, and each one can draw my attention at any moment. That's just not possible on a mobile device, and unlike a phone, an iPad is not designed to fit neatly in your hand with your fingers on the app switcher at all times. For me, it's perfect. If only I could run XCode on it...