I’d say, I’m primarily a very low volume gamer, so I don’t play a lot of games, and if I do, I don’t play them for long. And that certainly makes it easy to look at the news of a game releasing and to think, yeah, that’s probably neat, but if I’m buying another game then it’d be Undertale or Baba Is You or such, and it definitely doesn’t look as neat as those…
If you’ve got specific accounts you want to follow, you can get an RSS feed containing their public posts.
In terms of native clients, the closest such feature I know of, is that Fedilab (for Android) can remember your position in the timeline, so that you can resume reading.
If you primarily use one timeline, then you wouldn’t re-encounter already read posts, because they’re in the past from the remembered position.
I have to say, though, that it’s not the most reliable feature in the world…