Browsers shouldn't require accounts, and thankfully Firefox doesn't. But having a way to synchronize my passwords across all my devices is pretty important.
They had an implementation that did not require any accounts. They deemed that it's too confusing for users* to scan some QR codes (or type a bunch of characters), so they went with an account-based system.
*) Or whatever the real reason was. It was about time Mozilla started to have management issues so I absolutely won't be surprised if the goal was to "become an ecosystem" or "gather a userbase" (or whatever is management speak for forcing people to sign up).
Sure, strictly speaking, of course there were accounts as in "database records". However, users gave no details about themselves, and haven't signed up for anything. No long-term credentials, just a rendezvous point.
You used to just open two Firefoxes, start sync setup on the one, copy (or scan) a code to another - boom, done, they're talking to each other.
This niche use case which offers a marginal benefit even to those who want it, is a laughable mask for the assembly and deployment of one of the world's largest data harvesting networks, the browser 'sync' account
Linkding is great, and has some browser extensions to inject your favourites into relevant search pages on the likes of google, ddg, bing, etc, which was a nice idea I hadn't considered before
You value the syncing browser accounts offer. Personally I like being able to go between several of my own computers and not have all settings synced. It's not a fresh slate situation but it is a bit freeing to not carry all my digital baggage all the time.
What about bookmarks that I don’t necessarily want to be publicly known. Not even talking about anything potentially embarrassing. Things like where I bank or my doctor’s appointment booking page.
Presumably that's a small set of bookmarks which you could manage across devices.
Other options might be to have that personal homepage on a non-public machine (e.g., on your home or office LAN), behind a VPN, and/or password protected.
Another practice from days of yore was to export specific bookmarks and transfer those to other systems. This is indeed cumbersome with mobile browsers (I'm not sure these even offer bookmark import/export ... Looks as if that's synch-only for Firefox/Android, which is disappointing.
I like that my browser (Vivaldi, Brave) has accounts so my phone, desktop (2x OS), and laptop (2x OS) are always completely in sync, with no downgraded functionality if I choose to not use an account.