Sync options really hinge on what you're using. I bounced between my Kindle app and the actual e-reader for years, and the experience was a bit scattershot until I started sticking to platforms with proper single-sign-on. Most of the big apps now will track your page across devices if you're logged into the same account, no separate 'reading progress' login needed. It's baked into your regular profile. I noticed some webnovel platforms are a mess, though—you'll finish a chapter on your phone browser, open the tablet app, and it acts like you've never been there. Drives me up the wall.
That said, if you're asking about using a dedicated 'write reader' account specifically for syncing, I'm drawing a blank. The trend is toward unified accounts. Your progress, highlights, even your place in an audiobook, should just follow you if the service is designed well. The friction comes from fragmented ecosystems, not a lack of a special sync login.