For a while, I started to prefer an another web browser on Desktop, Min (besides Firefox). It's based on Chromium, but uses Electron for the interface. It's been around for a while, but I only discovered it a few years ago.

So this year's August, it got an early support for opening multiple pages on more than 1 window. To become a stable feature, it will take more time. However, Min's main developer had less free time to work on the project from September.