Is there a way to block those placeholders?
Sure. Put the code below in a user style addon like Stylus.
Anything you can identify by an identifier can be modified by your browser. You just need to know how to identify it. And it will not block replies on game pages, since those are not children of posts. It will also not block topics, but apparantly itch does not block topics either. Just the posting inside the topic.
This was tested for like a whole two minutes. (Personally I do not block people. I can use my scrollwheel just fine. But for some cases it sure would be helpful for out of sight, out of mind blocking).
@-moz-document domain("itch.io") {
div.post_grid:has(div.post_content > div.post_body.user_formatted > details.toggle_post_body) {
display: none;
}
div.post_grid:has(div.post_header > span.post_author > span.name_placeholder) {
display: none;
}
}