That's the goal of sample data: show samples / examples of what can be achieved in Magento. The widget is there to show how widgets work.
Would that not achieve the same effect?
Yes you can get the same effect by copy/paste the content of the CMS block in the CMS page content and remove the widget.
It becomes useful to use such widgets when you have several different blocks in your page and they have different purposes. E.g one widget for site presentation and one widget for current sale. You can disable the current sale block when the sale is over and thus you don't have to delete/comment content from the page
Best Answer
Go to
And then, post this below code in that field
You can set name of referenceContainer and referenceBlock name which you want to remove.
Hope, It will helpful for you !!