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.