Thank you, Otto! Thank you, Justin!

I am currently using Automattic's newspack theme, which is accompanied by a newspack blocks plugin. The newspack blocks plugin includes a Homepage Posts block that essentially does exactly what you referred to Justin. It enables one to choose a specific category and display the previously placed posts within that category. My tibesar.com homepage has several of these Homepage Posts blocks, which is really super cool.

So, it sounds like the Query Block is basically the same as this Homepage Posts block. This will be great since it enables all WordPress content developers to display an entire category of posts on Pages or Posts or the Homepage.

Again, thank you for your further explanations!