I disagree with the dashboard point, because the only thing that's worse than having little user traction is having no understanding of what user traction you do have. As the conclusion says, you should be focused on learning about your users and your domain - but that's exactly what a good dashboard should be helping you with!
I don't think that's the type of dashboard the article is talking about. I think the article is talking about dashboards IN their product. Like their product is about "help businesses do X" and the dashboard they are talking about is "let businesses using their product look at how much the product has helped them do X".
I have to disagree about dark mode being a 2nd-degree feature. It's an absolutely necessary bit of accessibility design. You don't have dark mode, you're stopping some people from being able to use your thing.
This comment is posted on HN, a site that doesn't offer dark mode but has succeeded anyway. I'm curious why you think lack of dark mode is a blocker for early adoption. Anyone who really cares can use browser extensions to create an ad-hoc dark mode, so workarounds exist.
Everyone has some feature that is a deal breaker for them. But an early stage start up doesn't have the resource to cater to all of them. Your market will forgive the absence of polish if it solves a problem for them well.
I also use Dark Reader, but it's buggy on a lot of sites, and it's ridiculous for people to be making things with a white theme anyways. People who shine flashlights in their eyes are short-sighted self-destructive morons.