I've been using vertical tabs in Firefox for longer than Edge existed. Currently I'm using the treestyle tabs extension, but there are others.
I find it interesting how we have a perfectly viable alternative in Firefox, but even many privacy informed users still promote Edge or Chrome. The author is a perfect example of this, he says he wants to box his "privacy exposure" to as few companies as possible. That would somehow make sense if all "companies" (in the broadest sense) were equal, but Firefox is made by a non for profit with the explicit goal of keeping the Internet free and private. And for the argument regarding Apple, Apple is perfectly happy to milk you for all your private data as well, they just keep it all to themselves. Why else the locking to their ecosystem.
I find it interesting how we have a perfectly viable alternative in Firefox, but even many privacy informed users still promote Edge or Chrome. The author is a perfect example of this, he says he wants to box his "privacy exposure" to as few companies as possible. That would somehow make sense if all "companies" (in the broadest sense) were equal, but Firefox is made by a non for profit with the explicit goal of keeping the Internet free and private. And for the argument regarding Apple, Apple is perfectly happy to milk you for all your private data as well, they just keep it all to themselves. Why else the locking to their ecosystem.