But other browsers do this (Vivaldi, Arc has split view) and its great. If the OS does it you have awkward additional spacing between those tabs and additional

But other browsers do this (Vivaldi, Arc has split view) and its great. If the OS does it you have awkward additional spacing between those tabs and additional browser chrome because the browser is unaware of the context you're in - comparing stuff side-by-side. I'd like an excuse to use Firefox again, but they've just given up on new UI functionality and I'd miss out on a lot by switching away from Arc.