After I scrolled past it once I dont want to see it again. Ideally I dont need to click anything on a post I am not interested in, not even a "mark as read" button.

The voyager web app literally just got this feature today.

I loved how slide for reddit solved that. You could set it to mark posts as read on scrolling them of screen and you'd have a floating button to hide read posts. So you could easily check for new comments or find new posts.

Yeah would love this! So far the app is working great so this would be a nice to have feature

Voting on a post marks it read

yes, if it's not too difficult

It does not help that some clients like Liftoff aggregate All feeds from 3-4 instances by default, meaning you see duplicates that aren’t even crossposts, and you cannot interact with most of them because “fetched via [instance], you are not logged in there”. While I have yet to find a client with seamless federation, Thunder comes very close.

There's a "hide read" feature. With smaller communities this tends to be a more common issue. If you're seeing it on your front page, then I'd recommend changing from Active to Hot sort for newer content.