Although I understand the OP's perspective open-source is a community effort and people should have a more proactive attitude and contribute when they feel things aren't okay. Most open-source developers aren't focused / don't have time for how things look (or at least not on the beginning). If you're a regular user and you can spend an hour taking a bunch of screenshots and improving a readme you'll be making more for the future the project that you might think.

As both user and developer - user CAN contribute but the developer/maintainer SHOULD add the screenshots.

This mentality explains a lot of open source.

There's both an ignorance and fear barrier to that.

A lot of people don't know they can, and don't know how. And even the ones that do know, often worry their contributions would be shit.

And there's folks that just don't think the project would accept that kind of submission.

I'm not contradicting your suggestion! It's a great thing to let people know that they can contribute without knowing how to code. Just adding in both an explanation as to why it's so rare, and hopefully allaying some of those worries for passersby.

If the app sucks, few people will add the screenshots. Therefore, most apps without screenshots will suck. So new apps will need the developer to add screenshots, or people will assume it sucks.

And we're back to square one. The developer has extra responsibility to highlight the features.

This. It should be the most sane configuration and fit most use cases and lead to an experience working out of the box.

Foreplay is important! Gotta get me excited for that app.

To be that dick, a headless component library is still meant to do something, show an example of it being used!

If you've written a "usage" section that showcases more than one uselessly simple example that doesn't even work in the project's current state, you're already far ahead of the average.

Even for a CLI tool, there should be a real world example showing how it works and what the output looks like. Eg, for jq:

$ cat file.json
{"field: "value"}
$ jq '.field' file.json
"value"

And a few other examples.

It scroobles obviously!

Including the documentation link, which only has incomplete getting started section

TODO

I imagine most single developer projects lack any design or UX so the screenshot would do little to encourage users to download.

I wish there was a way to give more props to open-source repos that do this.

I already star the project. But I'd love to say "Thanks for making a demo page it really helped!"

GitHub and GitLab both support inserting images into your README.md. Here's the syntax:

![Description of the image](https://path/to/image)

Not just a text file, a markdown file. And markdown has supported images since forever