I was using Arc as my main browser until they added the mandatory account requirement. It came around the same time they moved iCloud syncing to their own backend.
Now I just use Safari because all I do really is read stuff.
Arc is a very... Appley browser. Its marketing and communication pretends it's a world-changing product of massive importance, something everyone desires to own. In reality, it's a fork of someone else's browser with some UX tweaks.
I looked into it, but couldn't get over the pretentiousness. They seem to make plenty of money from either investors or customers because they're not bankrupt yet, so I guess there must be a demographic that likes being treated like that.
There's something funny about a browser pretending it's the best thing since sliced bread telling me to drag the downloaded application to the macOS dock after downloading the Windows setup file.
I use Arc for work. It has a few nice UX enhancements. None of those things that you mentioned affect me on a day to day basis. (Honestly, I don’t pay attention to marketing when making my decisions.)
Pretentious or not, Arc is pre-enshittification. Chrome, Edge and FF are not, which is what matters.
Chrome at launch was an extremely minimal web browser (hence the name, Chrome referred to the barest amount of window chrome around the web content) with decent system integration and essentially no Google service integration other than setting Google as the default search engine (maybe the only one, I don’t remember if there was even a setting to change it). There wasn’t a Mac version at first, but when that came, it has Keychain integration too rather than its own password manager.
It was fast. At some point it had its own install of Adobe Flash so you could get rid of your regular Flash install and run two browsers: one without Flash as your main, and use Chrome for those few websites that require Flash effectively isolating them from your regular web experience, until this eventually became moot, it was another WebKit browser, albeit with V8 instead of JavaScriptCore, and pioneered per tab process isolation so rather than your whole browser crashing, just that one tab would. Prior to Chrome, whole browser crashes were not uncommon, oftentimes because of Flash (giving another reason to want to isolate it, although plug-ins I think were also isolated).
What Chrome subsequently became is the very definition of enshittification, and you can pinpoint it to around the time Google started trying to force people to link their Chrome profiles to their Google Accounts.
"The Browser Company" does not want to be seen as a dumb pipe. You are not downloading a mere browser, but a "platform" for "experiencing the web as never before".
...and US tech companies take that as a reason to fill the app with feature bloat and then charge a subscription for it. Arc as a product is dead because the founders are of course pivoting to an "AI browser".
I removed it right away. I just want a browser, not whatever that was.