I wonder if lacking this behaviour by default extra incentivizes ephemeral reads and many pages. Though maybe there isn't much motivation for implementing it to

I wonder if lacking this behaviour by default extra incentivizes ephemeral reads and many pages. Though maybe there isn't much motivation for implementing it to begin with because the web ecosystem already heavily incentives this situation so sites don't consider it. It also seems like the most dependable split reading experience of a single webpage is to just offline save because pages online can easily change and go dead on you over time. And so maybe that is why apps for saving the web end up being where features like saving reading position or highlighting are instead implemented. For comments, I partially dealt with the issue by writing a bookmarklet that highlights the latest comments and jumps to the next one on the page with each click of it. It works pretty well for finding current activity, cutting across deep threads later in a discussions timeline, and seeing what I wouldn't have earlier.