A handful of states including California disallow this condition.
> have a clause that says that the employer owns everything you do while you’re working for them
Good companies will have a clause that says the employer owns everything you do in the relevant field of the company while working for them, explicitly naming that field.
If you work for a logistics company, you would be able to write your own video editor without any worry. If you work for a not-shitty company.
Yeah, this is my whole point. The rest of your comment, I agree with. In practice you're unlikely to have an issue for something orthogonal and especially something financially worthless.
But you might. There are a lot of people out there that have predatory attitudes towards IP, especially among C-level or would-be-C-level.
And companies that restrict to competing IP do exist.
Three times in my career I've returned hiring agreements with redlines and never once had them questioned or countered.
And even then there's normally a "Sufficiently Different Sector" requirement for those personal projects - which makes sense, but it is inevitably worded vague enough that it would likely require going to court for pretty much any project to show it's not directly related. And that would be near prohibitively expensive for me as an individual if the relationship actually became adversarial.