SEO gurus are lying to clients telling them that they need to worry about schema markup. Schema markup is what makes you see features like this in the search results, the stars or video duration. Lots of businesses spend a lot of time worrying about this stuff and pay a lot of money to SEOs to help them worry.
This is from Google directly. Google does not guarantee that your structured data will show up in search results. Also, most major site builders themes plugins already have schema built in.
If you have a website, you're probably already using schema and you don't realize it. You can use this tool to see right now what schema markup you're using. You only need to worry about schema when you're custom building a site or an app.
Or when you want to use it for something niche like a recipe, event or job posting. But again, even if you use it, Google might ignore it. There are things in SEO that are so much more important than schema markup.
That's why.