I know Firefox has a Split View feature; however, it’s not as convenient as Vivaldi or the Arc browser. I love how The browser company implemented the Split View screen. Firefox Split View is pretty limited, and I’m unsure if it has improved since its release.
What does the community think about that?
Here is an example of Arc browser split view:
Why not use your window manager / compositor for this feature?
For one thing, you don't have to struggle with a shrunken top toolbar.
There's a good reason a significant and increasing number of browsers (including Floorp, a Firefox fork) and other applications include view-splitting within them.
There's a reason Mozilla made Side View for Firefox.
https://addons.mozilla.org/en-US/firefox/addon/side-view/
I kind of feel this way about tabs, but everyone loves tabs so much I'm often too embarrassed to say anything.
Plasma (KDE) and Windows can both stack lots of windows just fine, so, why not let the window manager handle this and keep the browser more focused on browser tasks?
Wait, so instead of using tabs in your browser you just... put separate windows on top of each other, and use your taskbar/keyboard shortcut to switch between them?