I use, and love, the reMarkable paper tablet. They even market themselves as “Think without distractions”. It’s on the expensive side, but I’ve had one for over a year now (backed them on Kickstarter). I love that I can have tons of notebooks (for different topics, people, organizations, etc) but zero apps and no browser to distract me. It syncs over WiFi so I can get to my notes anywhere. I no longer carry around a laptop at work and instead use my reMarkable.
As an added bonus I also do most of my reading on it (ePub and PDFs).
It’s definitely not a cheap solution, but I really can’t stress enough the benefits of the simplicity and (for my ADD brain) the lack of distractions. The pen is a good twiddle toy too 😉