There are browser - Vivaldi for example - that allow you to place the tab strip on any edge you want. To me personally it just looks and feels wrong, maybe just because of years of exposure to tabs on the top, but I can not get used to it, even though I have to admit that the tab labels are much nicer to read on the left if you have sufficiently many tabs open.
Not only does Vivaldi allow you to do that, but you can customise every menu in the program. I've modified the context menu to have exactly the things I want, in the order I want them. This is what Firefox should have been.
It's too bad I'll have to dump Vivaldi soon, now that Google is killing adblockers.
I’ve been daily driving Arc for a while now and I’m very sold on the tabs on the left. I think it’s the mix of smart folders, pinned pages, and knowing that stale tabs will be automatically closed so it doesn’t ever feel too cluttered. Also the quick show/hide with Cmd+s is perfect, especially since it’s been quite a while since I’ve wanted to Save a webpage.
Side note: it infuriates me that Microsoft’s web-Office will “helpfully” remind me that it auto saves when I do Cmd+s but also captures the event so that Arc can’t handle it. Which reminds me…I can probably whip up a quick Boost to get rid of that - yay rubber ducking in the comments!