Author here — me and a friend have been working on Brick for the past several months.
It works like Notion as in "all your edits are instantly visible" — from experience, this feels very different from blogging on Wordpress or making a static site in a git repo.
I love static sites but I'm not going back to them. I can experiment much more easily with Brick.
You can do something similar with Notion, but Notion is aimed at management or personal knowledge-bases, and it shows. We have a different focus. E.g. Notion is unlikely to ever have email subscriptions or ways to let people pay for your writing, while we very well might in the future. Notion also doesn't support custom domains out of the box, or custom CSS.
Try it out! Brick is free and has no ads. The only thing is that you need a premium plan (less than $2/mo) for custom domains.